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How to Setup a Mail Server on CentOS 5

This tutorial sets up and configures the following:

Primary packages

  • sendmail
  • spamassassin
  • milter-greylist
  • GeoIP
  • clamav
  • spamassassin-milter
  • clamav-milter
  • dovecot

Addons to spamassassin

  • SPF
  • DKIM

Optional Extras

  • spf-milter

NOTE: I’ll discuss how to setup the spf-milter, towards the end of this post but I now consider this an OPTIONAL package after talking with the maintainer of the city-fan.org repo, Paul Howarth. In talking with Paul, it turns out that spamassassin now has the ability to perform SPF checks based on a sender’s domain and IP address. This makes installing the spf-milter redundant and unecessary.

Getting Started

I found this very helpful YUM repository, city-fan.org that contains pretty much everything I needed to accomplish this, minus the ClamAV packages. For those I looked to another repository, rpmforge. To get started, I installed the repo rpm files below.

Setting up city-fan.org repo
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# install yum repo package
rpm -Uvh http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-9.rhel5.noarch.rpm
 
# import repo's GPG Key
rpm --import http://www.city-fan.org/ftp/contrib/yum-repo/CITY-FAN.ORG-GPG-KEY
 
# perform an initial update
yum update
Setting up rpmforge repo
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# install yum repo package
rpm -Uvh http://dag.wieers.com/rpm/packages/rpmforge-release/rpmforge-release-0.3.6-1.el5.rf.i386.rpm
 
# import repo's GPG Key
rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt
 
# perform an initial update
yum update
Setting up Spamassassin
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yum install spamassassin \
 spamass-milter

Setup /etc/sysconfig/spamassassin

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# Options to spamd
SPAMDOPTIONS="-d -c -m5 -H"

Setup /etc/sysconfig/spamass-milter

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### Override for your different local config
#SOCKET=/var/run/spamass-milter/spamass-milter.sock
 
### Standard parameters for spamass-milter are:
### -P /var/run/spamass-milter.pid (PID file)
###
### Note that the -f parameter for running the milter in the background
### is not required because the milter runs in a wrapper script that
### backgrounds itself
###
### You may add another parameters here, see spamass-milter(1)
#EXTRA_FLAGS="-m -r 15"

Add the following to sendmail.mc and re-make sendmail.cf

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dnl **
dnl ** enable spamassassin-milter to scan for spam using spamassassin **
dnl **
INPUT_MAIL_FILTER(`spamassassin', `S=unix:/var/run/spamass-milter/spamass-milter.sock, F=, T=C:15m;S:4m;R:4m;E:10m')dnl
define(`confMILTER_MACROS_CONNECT',`t, b, j, _, {daemon_name}, {if_name}, {if_addr}')dnl
define(`confMILTER_MACROS_HELO',`s, {tls_version}, {cipher}, {cipher_bits}, {cert_subject}, {cert_issuer}')dnl
Setting up SPF (NOTE: used by spamassassin, NOT the milter!)
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# install perl-Mail-SPF
yum install perl-Mail-SPF
 
# restart spamassassin (in order to detect the spf plugin)
/etc/init.d/spamassassin restart

Spamassassin will automatically detect that SPF has been installed and will start using it as part of its scoring of each email. You can confirm that it’s working with this test.

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spamassassin -D <  /usr/share/doc/spamassassin-3.2.5/sample-spam.txt 2>&1 |grep -i spf
[18108] dbg: config: read file /usr/share/spamassassin/25_spf.cf
[18108] dbg: config: read file /usr/share/spamassassin/60_whitelist_spf.cf
[18108] dbg: plugin: loading Mail::SpamAssassin::Plugin::SPF from @INC
[18108] dbg: spf: checking to see if the message has a Received-SPF header that we can use
[18108] dbg: spf: using Mail::SPF for SPF checks
[18108] dbg: spf: no suitable relay for spf use found, skipping SPF-helo check
[18108] dbg: spf: already checked for Received-SPF headers, proceeding with DNS based checks
[18108] dbg: spf: no suitable relay for spf use found, skipping SPF check
[18108] dbg: spf: def_spf_whitelist_from: already checked spf and didn't get pass, skipping whitelist check
[18108] dbg: spf: whitelist_from_spf: already checked spf and didn't get pass, skipping whitelist check
Setting up DKIM

This module implements the various components of the DKIM and DomainKeys message-signing and verifying standards for Internet mail. It currently tries to implement these specifications:
* RFC4871, for DKIM
* RFC4870, for DomainKeys

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yum install perl-Mail-DKIM

Spamassassin will automatically detect that DKIM has been installed and will start using it as part of its scoring of each email. I confirmed that it was working by sending myself an email from my gmail account and copying this email, make sure to include the full headers, into a text file. In my case I called this file test_email.txt.

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spamassassin -D < ~/sam2.txt 2>&1 |grep -i dk
[18334] dbg: config: read file /usr/share/spamassassin/25_dkim.cf
[18334] dbg: config: read file /usr/share/spamassassin/60_whitelist_dk.cf
[18334] dbg: config: read file /usr/share/spamassassin/60_whitelist_dkim.cf
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
       	bh=8PW6kvDkcUGo7mGimEUrTlMVS5Y1dFw/IjjLn1WnNLw=;
Setting up GeoIP

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yum install GeoIP

This package will be leveraged by milter-greylist to perform greylisting based on geographic locations of the sender’s IP address.

Setting up milter-greylist

The latest version can be downloaded from this page

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wget http://www.mailscanner.info/files/greylist/milter-greylist-4.0-4.jkf.el5.i386.rpm
yum --nogpgcheck install milter-greylist-4.0-4.jkf.el5.i386.rpm
Setting up ClamAV
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yum install clamav \
 clamav-db \
 clamav-milter \
 clamd

Setup /etc/sysconfig/clamav-milter

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### Simple config file for clamav-milter, you should
### read the documentation and tweak it as you wish.
 
CLAMAV_FLAGS="--config-file=/etc/clamav-milter.conf"

Setup /etc/clamav-milter.conf

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##
## Example config file for clamav-milter
##
 
# Comment or remove the line below.
#Example
 
 
##
## Main options
##
 
# Define the interface through which we communicate with sendmail
# This option is mandatory! Possible formats are:
# [[unix|local]:]/path/to/file - to specify a unix domain socket
# inet:port@[hostname|ip-address] - to specify an ipv4 socket
# inet6:port@[hostname|ip-address] - to specify an ipv6 socket
#
# Default: no default
MilterSocket unix:/var/clamav/clmilter.socket
#MilterSocket inet:7357
 
# Remove stale socket after unclean shutdown.
#
# Default: yes
#FixStaleSocket yes
 
# Run as another user (clamav-milter must be started by root for this option to work)
#
# Default: unset (don't drop privileges)
User clamav
 
# Initialize supplementary group access (clamav-milter must be started by root).
#
# Default: no
AllowSupplementaryGroups yes
 
# Waiting for data from clamd will timeout after this time (seconds).
# Value of 0 disables the timeout.
#
# Default: 120
#ReadTimeout 300
 
# Don't fork into background.
#
# Default: no
#Foreground yes
 
# Chroot to the specified directory.
# Chrooting is performed just after reading the config file and before dropping privileges.
#
# Default: unset (don't chroot)
#Chroot /newroot
 
# This option allows you to save a process identifier of the listening
# daemon (main thread).
#
# Default: disabled
#PidFile /var/run/clamav-milter.pid
 
# Optional path to the global temporary directory.
# Default: system specific (usually /tmp or /var/tmp).
#
#TemporaryDirectory /var/tmp
 
##
## Clamd options
##
 
# Define the clamd socket to connect to for scanning.
# This option is mandatory! Syntax:
# ClamdSocket unix:path
# ClamdSocket tcp:host:port
# The first syntax specifies a local unix socket (needs an absolute path) e.g.:
#     ClamdSocket unix:/var/run/clamd/clamd.socket
# The second syntax specifies a tcp local or remote tcp socket: the
# host can be a hostname or an ip address; the ":port" field is only required
# for IPv6 addresses, otherwise it defaults to 3310
#     ClamdSocket tcp:192.168.0.1
#
# This option can be repeated several times with different sockets or even
# with the same socket: clamd servers will be selected in a round-robin fashion.
#
# Default: no default
ClamdSocket unix:/var/run/clamav/clamd.sock
 
 
##
## Exclusions
##
 
# Messages originating from these hosts/networks will not be scanned
# This option takes a host(name)/mask pair in CIRD notation and can be
# repeated several times. If "/mask" is omitted, a host is assumed.
# To specify a locally orignated, non-smtp, email use the keyword "local"
#
# Default: unset (scan everything regardless of the origin)
#LocalNet local
#LocalNet 192.168.0.0/24
#LocalNet 1111:2222:3333::/48
 
# This option specifies a file which contains a list of basic POSIX regular
# expressions. Addresses (sent to or from - see below) matching these regexes
# will not be scanned.  Optionally each line can start with the string "From:"
# or "To:" (note: no whitespace after the colon) indicating if it is, 
# respectively, the sender or recipient that is to be whitelisted.
# If the field is missing, "To:" is assumed.
# Lines starting with #, : or ! are ignored.
#
# Default unset (no exclusion applied)
#Whitelist /etc/whitelisted_addresses
 
# Messages from authenticated SMTP users matching this extended POSIX
# regular expression (egrep-like) will not be scanned.
# Note: this is the AUTH login name!
#
# Default: unset (no whitelisting based on SMTP auth)
#SkipAuthenticated ^(tom|dick|henry)$
 
 
##
## Actions
##
 
# The following group of options controls the delievery process under
# different circumstances.
# The following actions are available:
# - Accept
#   The message is accepted for delievery
# - Reject
#   Immediately refuse delievery (a 5xx error is returned to the peer)
# - Defer
#   Return a temporary failure message (4xx) to the peer
# - Blackhole (not available for OnFail)
#   Like accept but the message is sent to oblivion
# - Quarantine (not available for OnFail)
#   Like accept but message is quarantined instead of being delivered
#   In sendmail the quarantine queue can be examined via mailq -qQ
#   For Postfix this causes the message to be accepted but placed on hold
# 
# Action to be performed on clean messages (mostly useful for testing)
# Default Accept
#OnClean Accept
 
# Action to be performed on infected messages
# Default: Quarantine
#OnInfected Quarantine
 
# Action to be performed on error conditions (this includes failure to
# allocate data structures, no scanners available, network timeouts,
# unknown scanner replies and the like)
# Default Defer
#OnFail Defer
 
# This option allows to set a specific rejection reason for infected messages
# and it's therefore only useful together with "OnInfected Reject"
# The string "%v", if present, will be replaced with the virus name.
# Default: MTA specific
#RejectMsg 
 
# If this option is set to Yes, an "X-Virus-Scanned" and an "X-Virus-Status"
# headers will be attached to each processed message, possibly replacing
# existing headers. 
# Default: No
#AddHeader Yes
 
 
##
## Logging options
##
 
# Uncomment this option to enable logging.
# LogFile must be writable for the user running daemon.
# A full path is required.
#
# Default: disabled
LogFile /var/log/clamav/clamav-milter.log
 
# By default the log file is locked for writing - the lock protects against
# running clamav-milter multiple times.
# This option disables log file locking.
#
# Default: no
#LogFileUnlock yes
 
# Maximum size of the log file.
# Value of 0 disables the limit.
# You may use 'M' or 'm' for megabytes (1M = 1m = 1048576 bytes)
# and 'K' or 'k' for kilobytes (1K = 1k = 1024 bytes). To specify the size
# in bytes just don't use modifiers.
#
# Default: 1M
LogFileMaxSize 0
 
# Log time with each message.
#
# Default: no
LogTime yes
 
# Use system logger (can work together with LogFile).
#
# Default: no
LogSyslog yes
 
# Specify the type of syslog messages - please refer to 'man syslog'
# for facility names.
#
# Default: LOG_LOCAL6
#LogFacility LOG_MAIL
 
# Enable verbose logging.
#
# Default: no
#LogVerbose yes
 
# This option allows to tune what is logged when a message is infected.
# Possible values are Off (the default - nothing is logged),
# Basic (minimal info logged), Full (verbose info logged)
#
# Default: disabled
#LogInfected Basic
 
 
##
## Limits
##
 
# Messages larger than this value won't be scanned.
# Make sure this value is lower or equal than StreamMaxLength in clamd.conf
#
# Default: 25M
#MaxFileSize 10M

Setup /etc/clamd.conf

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##
## Example config file for the Clam AV daemon
## Please read the clamd.conf(5) manual before editing this file.
##
 
 
# Comment or remove the line below.
#Example
 
# Uncomment this option to enable logging.
# LogFile must be writable for the user running daemon.
# A full path is required.
# Default: disabled
LogFile /var/log/clamav/clamd.log
 
# By default the log file is locked for writing - the lock protects against
# running clamd multiple times (if want to run another clamd, please
# copy the configuration file, change the LogFile variable, and run
# the daemon with --config-file option).
# This option disables log file locking.
# Default: no
#LogFileUnlock yes
 
# Maximum size of the log file.
# Value of 0 disables the limit.
# You may use 'M' or 'm' for megabytes (1M = 1m = 1048576 bytes)
# and 'K' or 'k' for kilobytes (1K = 1k = 1024 bytes). To specify the size
# in bytes just don't use modifiers.
# Default: 1M
LogFileMaxSize 0
 
# Log time with each message.
# Default: no
LogTime yes
 
# Also log clean files. Useful in debugging but drastically increases the
# log size.
# Default: no
#LogClean yes
 
# Use system logger (can work together with LogFile).
# Default: no
LogSyslog yes
 
# Specify the type of syslog messages - please refer to 'man syslog'
# for facility names.
# Default: LOG_LOCAL6
#LogFacility LOG_MAIL
 
# Enable verbose logging.
# Default: no
#LogVerbose yes
 
# This option allows you to save a process identifier of the listening
# daemon (main thread).
# Default: disabled
PidFile /var/run/clamav/clamd.pid
 
# Optional path to the global temporary directory.
# Default: system specific (usually /tmp or /var/tmp).
TemporaryDirectory /var/tmp
 
# Path to the database directory.
# Default: hardcoded (depends on installation options)
DatabaseDirectory /var/clamav
 
# The daemon can work in local mode, network mode or both. 
# Due to security reasons we recommend the local mode.
 
# Path to a local socket file the daemon will listen on.
# Default: disabled (must be specified by a user)
LocalSocket /var/run/clamav/clamd.sock
 
# Remove stale socket after unclean shutdown.
# Default: yes
FixStaleSocket yes
 
# TCP port address.
# Default: no
TCPSocket 3310
 
# TCP address.
# By default we bind to INADDR_ANY, probably not wise.
# Enable the following to provide some degree of protection
# from the outside world.
# Default: no
TCPAddr 127.0.0.1
 
# Maximum length the queue of pending connections may grow to.
# Default: 15
MaxConnectionQueueLength 30
 
# Clamd uses FTP-like protocol to receive data from remote clients.
# If you are using clamav-milter to balance load between remote clamd daemons
# on firewall servers you may need to tune the options below.
 
# Close the connection when the data size limit is exceeded.
# The value should match your MTA's limit for a maximum attachment size.
# Default: 25M
#StreamMaxLength 10M
 
# Limit port range.
# Default: 1024
#StreamMinPort 30000
# Default: 2048
#StreamMaxPort 32000
 
# Maximum number of threads running at the same time.
# Default: 10
MaxThreads 50
 
# Waiting for data from a client socket will timeout after this time (seconds).
# Value of 0 disables the timeout.
# Default: 120
ReadTimeout 300
 
# This option specifies the time (in seconds) after which clamd should
# timeout if a client doesn't provide any initial command after connecting.
# Default: 5
#CommandReadTimeout 5
 
# This option specifies how long to wait (in miliseconds) if the send buffer is full.
# Keep this value low to prevent clamd hanging
#
# Default: 500
#SendBufTimeout 200
 
# Maximum number of queued items (including those being processed by MaxThreads threads)
# It is recommended to have this value at least twice MaxThreads if possible.
# WARNING: you shouldn't increase this too much to avoid running out  of file descriptors,
# the following condition should hold:
# MaxThreads*MaxRecursion + (MaxQueue - MaxThreads) + 6< RLIMIT_NOFILE (usual max is 1024)
#
# Default: 100
#MaxQueue 200
 
# Waiting for a new job will timeout after this time (seconds).
# Default: 30
#IdleTimeout 60
 
# Don't scan files and directories matching regex
# This directive can be used multiple times
# Default: scan all
#ExcludePath ^/proc/
#ExcludePath ^/sys/
 
# Maximum depth directories are scanned at.
# Default: 15
#MaxDirectoryRecursion 20
 
# Follow directory symlinks.
# Default: no
#FollowDirectorySymlinks yes
 
# Follow regular file symlinks.
# Default: no
#FollowFileSymlinks yes
 
# Perform a database check.
# Default: 600 (10 min)
#SelfCheck 600
 
# Execute a command when virus is found. In the command string %v will
# be replaced with the virus name.
# Default: no
#VirusEvent /usr/local/bin/send_sms 123456789 "VIRUS ALERT: %v"
 
# Run as another user (clamd must be started by root for this option to work)
# Default: don't drop privileges
User clamav
 
# Initialize supplementary group access (clamd must be started by root).
# Default: no
AllowSupplementaryGroups yes
 
# Stop daemon when libclamav reports out of memory condition.
#ExitOnOOM yes
 
# Don't fork into background.
# Default: no
#Foreground yes
 
# Enable debug messages in libclamav.
# Default: no
#Debug yes
 
# Do not remove temporary files (for debug purposes).
# Default: no
#LeaveTemporaryFiles yes
 
# Detect Possibly Unwanted Applications.
# Default: no
#DetectPUA yes
 
# Exclude a specific PUA category. This directive can be used multiple times.
# See http://www.clamav.net/support/pua for the complete list of PUA
# categories.
# Default: Load all categories (if DetectPUA is activated)
#ExcludePUA NetTool
#ExcludePUA PWTool
 
# Only include a specific PUA category. This directive can be used multiple
# times.
# Default: Load all categories (if DetectPUA is activated)
#IncludePUA Spy
#IncludePUA Scanner
#IncludePUA RAT
 
# In some cases (eg. complex malware, exploits in graphic files, and others),
# ClamAV uses special algorithms to provide accurate detection. This option
# controls the algorithmic detection.
# Default: yes
#AlgorithmicDetection yes
 
 
##
## Executable files
##
 
# PE stands for Portable Executable - it's an executable file format used
# in all 32 and 64-bit versions of Windows operating systems. This option allows
# ClamAV to perform a deeper analysis of executable files and it's also
# required for decompression of popular executable packers such as UPX, FSG,
# and Petite.
# Default: yes
ScanPE yes
 
# Executable and Linking Format is a standard format for UN*X executables.
# This option allows you to control the scanning of ELF files.
# Default: yes
ScanELF yes
 
# With this option clamav will try to detect broken executables (both PE and
# ELF) and mark them as Broken.Executable.
# Default: no
DetectBrokenExecutables yes
 
 
##
## Documents
##
 
# This option enables scanning of OLE2 files, such as Microsoft Office
# documents and .msi files.
# Default: yes
ScanOLE2 yes
 
# This option enables scanning within PDF files.
# Default: yes
#ScanPDF yes
 
 
##
## Mail files
##
 
# Enable internal e-mail scanner.
# Default: yes
ScanMail yes
 
# If an email contains URLs ClamAV can download and scan them.
# WARNING: This option may open your system to a DoS attack.
#	   Never use it on loaded servers.
# Default: no
#MailFollowURLs no
 
# Scan RFC1341 messages split over many emails.
# You will need to periodically clean up $TemporaryDirectory/clamav-partial directory.
# WARNING: This option may open your system to a DoS attack.
#	   Never use it on loaded servers.
# Default: no
#ScanPartialMessages yes
 
 
# With this option enabled ClamAV will try to detect phishing attempts by using
# signatures.
# Default: yes
#PhishingSignatures yes
 
# Scan URLs found in mails for phishing attempts using heuristics.
# Default: yes
#PhishingScanURLs yes
 
# Always block SSL mismatches in URLs, even if the URL isn't in the database.
# This can lead to false positives.
#
# Default: no
#PhishingAlwaysBlockSSLMismatch no
 
# Always block cloaked URLs, even if URL isn't in database.
# This can lead to false positives.
#
# Default: no
#PhishingAlwaysBlockCloak no
 
# Allow heuristic match to take precedence.
# When enabled, if a heuristic scan (such as phishingScan) detects
# a possible virus/phish it will stop scan immediately. Recommended, saves CPU
# scan-time.
# When disabled, virus/phish detected by heuristic scans will be reported only at
# the end of a scan. If an archive contains both a heuristically detected
# virus/phish, and a real malware, the real malware will be reported
#
# Keep this disabled if you intend to handle "*.Heuristics.*" viruses 
# differently from "real" malware.
# If a non-heuristically-detected virus (signature-based) is found first, 
# the scan is interrupted immediately, regardless of this config option.
#
# Default: no
#HeuristicScanPrecedence yes
 
##
## Data Loss Prevention (DLP)
##
 
# Enable the DLP module
# Default: No
#StructuredDataDetection yes
 
# This option sets the lowest number of Credit Card numbers found in a file
# to generate a detect.
# Default: 3
#StructuredMinCreditCardCount 5
 
# This option sets the lowest number of Social Security Numbers found
# in a file to generate a detect.
# Default: 3
#StructuredMinSSNCount 5
 
# With this option enabled the DLP module will search for valid
# SSNs formatted as xxx-yy-zzzz
# Default: yes
#StructuredSSNFormatNormal yes
 
# With this option enabled the DLP module will search for valid
# SSNs formatted as xxxyyzzzz
# Default: no
#StructuredSSNFormatStripped yes
 
 
##
## HTML
##
 
# Perform HTML normalisation and decryption of MS Script Encoder code.
# Default: yes
#ScanHTML yes
 
 
##
## Archives
##
 
# ClamAV can scan within archives and compressed files.
# Default: yes
ScanArchive yes
 
# Mark encrypted archives as viruses (Encrypted.Zip, Encrypted.RAR).
# Default: no
ArchiveBlockEncrypted no
 
 
##
## Limits
##
 
# The options below protect your system against Denial of Service attacks
# using archive bombs.
 
# This option sets the maximum amount of data to be scanned for each input file.
# Archives and other containers are recursively extracted and scanned up to this
# value.
# Value of 0 disables the limit
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 100M
#MaxScanSize 150M
 
# Files larger than this limit won't be scanned. Affects the input file itself
# as well as files contained inside it (when the input file is an archive, a
# document or some other kind of container).
# Value of 0 disables the limit.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 25M
#MaxFileSize 30M
 
# Nested archives are scanned recursively, e.g. if a Zip archive contains a RAR
# file, all files within it will also be scanned. This options specifies how
# deeply the process should be continued.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Value of 0 disables the limit.
# Default: 16
#MaxRecursion 10
 
# Number of files to be scanned within an archive, a document, or any other
# container file.
# Value of 0 disables the limit.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 10000
#MaxFiles 15000
 
 
##
## Clamuko settings
## WARNING: This is experimental software. It is very likely it will hang
##	    up your system!!!
##
 
# Enable Clamuko. Dazuko (/dev/dazuko) must be configured and running.
# Default: no
#ClamukoScanOnAccess yes
 
# Set access mask for Clamuko.
# Default: no
#ClamukoScanOnOpen yes
#ClamukoScanOnClose yes
#ClamukoScanOnExec yes
 
# Set the include paths (all files inside them will be scanned). You can have
# multiple ClamukoIncludePath directives but each directory must be added
# in a seperate line.
# Default: disabled
#ClamukoIncludePath /home
#ClamukoIncludePath /students
 
# Set the exclude paths. All subdirectories are also excluded.
# Default: disabled
#ClamukoExcludePath /home/bofh
 
# Don't scan files larger than ClamukoMaxFileSize
# Value of 0 disables the limit.
# Default: 5M
#ClamukoMaxFileSize 10M
Setting up Dovecot
1
yum install dovecot

Setup /etc/dovecot.conf

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## Dovecot configuration file
 
# If you're in a hurry, see http://wiki.dovecot.org/QuickConfiguration
 
# "dovecot -n" command gives a clean output of the changed settings. Use it
# instead of copy&pasting this file when posting to the Dovecot mailing list.
 
# '#' character and everything after it is treated as comments. Extra spaces
# and tabs are ignored. If you want to use either of these explicitly, put the
# value inside quotes, eg.: key = "# char and trailing whitespace  "
 
# Default values are shown for each setting, it's not required to uncomment
# any of the lines.
 
# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/
 
# Protocols we want to be serving: imap imaps pop3 pop3s managesieve
# If you only want to use dovecot-auth, you can set this to "none".
#protocols = imap imaps pop3 pop3s
protocols = imap imaps pop3 pop3s
 
# A space separated list of IP or host addresses where to listen in for
# connections. "*" listens in all IPv4 interfaces. "[::]" listens in all IPv6
# interfaces. Use "*, [::]" for listening both IPv4 and IPv6.
#
# If you want to specify ports for each service, you will need to configure
# these settings inside the protocol imap/pop3/managesieve { ... } section, 
# so you can specify different ports for IMAP/POP3/MANAGESIEVE. For example:
#   protocol imap {
#     listen = *:10143
#     ssl_listen = *:10943
#     ..
#   }
#   protocol pop3 {
#     listen = *:10100
#     ..
#   }
#   protocol managesieve {
#     listen = *:12000
#     ..
#   }
#listen = *, [::]
 
# Disable LOGIN command and all other plaintext authentications unless
# SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
# matches the local IP (ie. you're connecting from the same computer), the
# connection is considered secure and plaintext authentication is allowed.
#disable_plaintext_auth = no
 
# Should all IMAP and POP3 processes be killed when Dovecot master process
# shuts down. Setting this to "no" means that Dovecot can be upgraded without
# forcing existing client connections to close (although that could also be
# a problem if the upgrade is eg. because of a security fix). This however
# means that after master process has died, the client processes can't write
# to log files anymore.
#shutdown_clients = yes
 
##
## Logging
##
 
# Log file to use for error messages, instead of sending them to syslog.
# /dev/stderr can be used to log into stderr.
#log_path = 
 
# Log file to use for informational and debug messages.
# Default is the same as log_path.
#info_log_path = 
 
# Prefix for each line written to log file. % codes are in strftime(3)
# format.
#log_timestamp = "%b %d %H:%M:%S "
 
# Syslog facility to use if you're logging to syslog. Usually if you don't
# want to use "mail", you'll use local0..local7. Also other standard
# facilities are supported.
#syslog_facility = mail
 
##
## SSL settings
##
 
# IP or host address where to listen in for SSL connections. Remember to also
# add imaps and/or pop3s to protocols setting. Defaults to same as "listen"
# setting if not specified.
#ssl_listen =
 
# SSL/TLS support: yes, no, required. <doc/wiki/SSL>
#ssl = yes
 
# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before
# dropping root privileges, so keep the key file unreadable by anyone but
# root. Included doc/mkcert.sh can be used to easily generate self-signed
# certificate, just make sure to update the domains in dovecot-openssl.cnf
ssl_cert_file = /etc/pki/dovecot/certs/dovecot.pem
ssl_key_file = /etc/pki/dovecot/private/dovecot.pem
 
# If key file is password protected, give the password here. Alternatively
# give it when starting dovecot with -p parameter. Since this file is often
# world-readable, you may want to place this setting instead to a different
# root owned 0600 file by using !include_try <path>.
#ssl_key_password =
 
# File containing trusted SSL certificate authorities. Set this only if you
# intend to use ssl_verify_client_cert=yes. The CAfile should contain the
# CA-certificate(s) followed by the matching CRL(s).
#ssl_ca_file = 
 
# Request client to send a certificate. If you also want to require it, set
# ssl_require_client_cert=yes in auth section.
#ssl_verify_client_cert = no
 
# Which field from certificate to use for username. commonName and
# x500UniqueIdentifier are the usual choices. You'll also need to set
# ssl_username_from_cert=yes.
#ssl_cert_username_field = commonName
 
# How often to regenerate the SSL parameters file. Generation is quite CPU
# intensive operation. The value is in hours, 0 disables regeneration
# entirely.
#ssl_parameters_regenerate = 168
 
# SSL ciphers to use
#ssl_cipher_list = ALL:!LOW:!SSLv2
 
# Show protocol level SSL errors.
#verbose_ssl = no
 
##
## Login processes
##
 
# <doc/wiki/LoginProcess.txt>
 
# Directory where authentication process places authentication UNIX sockets
# which login needs to be able to connect to. The sockets are created when
# running as root, so you don't have to worry about permissions. Note that
# everything in this directory is deleted when Dovecot is started.
#login_dir = /var/run/dovecot/login
 
# chroot login process to the login_dir. Only reason not to do this is if you
# wish to run the whole Dovecot without roots. <doc/wiki/Rootless.txt>
#login_chroot = yes
 
# User to use for the login process. Create a completely new user for this,
# and don't use it anywhere else. The user must also belong to a group where
# only it has access, it's used to control access for authentication process.
# Note that this user is NOT used to access mails. <doc/wiki/UserIds.txt>
#login_user = dovecot
 
# Set max. process size in megabytes. If you don't use
# login_process_per_connection you might need to grow this.
#login_process_size = 64
 
# Should each login be processed in it's own process (yes), or should one
# login process be allowed to process multiple connections (no)? Yes is more
# secure, espcially with SSL/TLS enabled. No is faster since there's no need
# to create processes all the time.
#login_process_per_connection = yes
 
# Number of login processes to keep for listening new connections.
#login_processes_count = 3
 
# Maximum number of login processes to create. The listening process count
# usually stays at login_processes_count, but when multiple users start logging
# in at the same time more extra processes are created. To prevent fork-bombing
# we check only once in a second if new processes should be created - if all
# of them are used at the time, we double their amount until the limit set by
# this setting is reached.
#login_max_processes_count = 128
 
# Maximum number of connections allowed per each login process. This setting
# is used only if login_process_per_connection=no. Once the limit is reached,
# the process notifies master so that it can create a new login process.
#login_max_connections = 256
 
# Greeting message for clients.
#login_greeting = Dovecot ready.
 
# Space separated list of trusted network ranges. Connections from these
# IPs are allowed to override their IP addresses and ports (for logging and
# for authentication checks). disable_plaintext_auth is also ignored for
# these networks. Typically you'd specify your IMAP proxy servers here.
#login_trusted_networks =
 
# Space-separated list of elements we want to log. The elements which have
# a non-empty variable value are joined together to form a comma-separated
# string.
#login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c
 
# Login log format. %$ contains login_log_format_elements string, %s contains
# the data we want to log.
#login_log_format = %$: %s
 
##
## Mailbox locations and namespaces
##
 
# Location for users' mailboxes. This is the same as the old default_mail_env
# setting. The default is empty, which means that Dovecot tries to find the
# mailboxes automatically. This won't work if the user doesn't have any mail
# yet, so you should explicitly tell Dovecot the full location.
#
# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)
# isn't enough. You'll also need to tell Dovecot where the other mailboxes are
# kept. This is called the "root mail directory", and it must be the first
# path given in the mail_location setting.
#
# There are a few special variables you can use, eg.:
#
#   %u - username
#   %n - user part in user@domain, same as %u if there's no domain
#   %d - domain part in user@domain, empty if there's no domain
#   %h - home directory
#
# See doc/wiki/Variables.txt for full list. Some examples:
#
#   mail_location = maildir:~/Maildir
#   mail_location = mbox:~/mail:INBOX=/var/mail/%u
#   mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
#
# <doc/wiki/MailLocation.txt>
#
#mail_location =
mail_location = mbox:~/Mail:INBOX=/home/%u/Mail/INBOX
 
# If you need to set multiple mailbox locations or want to change default
# namespace settings, you can do it by defining namespace sections.
#
# You can have private, shared and public namespaces. Private namespaces
# are for user's personal mails. Shared namespaces are for accessing other
# users' mailboxes that have been shared. Public namespaces are for shared
# mailboxes that are managed by sysadmin. If you create any shared or public
# namespaces you'll typically want to enable ACL plugin also, otherwise all
# users can access all the shared mailboxes, assuming they have permissions
# on filesystem level to do so.
#
# REMEMBER: If you add any namespaces, the default namespace must be added
# explicitly, ie. mail_location does nothing unless you have a namespace
# without a location setting. Default namespace is simply done by having a
# namespace with empty prefix.
#namespace private {
   # Hierarchy separator to use. You should use the same separator for all
   # namespaces or some clients get confused. '/' is usually a good one.
   # The default however depends on the underlying mail storage format.
   #separator = 
 
   # Prefix required to access this namespace. This needs to be different for
   # all namespaces. For example "Public/".
   #prefix = 
 
   # Physical location of the mailbox. This is in same format as
   # mail_location, which is also the default for it.
   #location =
 
   # There can be only one INBOX, and this setting defines which namespace
   # has it.
   #inbox = no
 
   # If namespace is hidden, it's not advertised to clients via NAMESPACE
   # extension. You'll most likely also want to set list=no. This is mostly
   # useful when converting from another server with different namespaces which
   # you want to deprecate but still keep working. For example you can create
   # hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/".
   #hidden = yes
 
   # Show the mailboxes under this namespace with LIST command. This makes the
   # namespace visible for clients that don't support NAMESPACE extension.
   # "children" value lists child mailboxes, but hides the namespace prefix.
   #list = yes
 
   # Namespace handles its own subscriptions. If set to "no", the parent
   # namespace handles them (empty prefix should always have this as "yes")
   #subscriptions = yes
#}
 
# Example shared namespace configuration
#namespace shared {
   #separator = /
 
   # Mailboxes are visible under "shared/user@domain/"
   # %%n, %%d and %%u are expanded to the destination user.
   #prefix = shared/%%u/
 
   # Mail location for other users' mailboxes. Note that %variables and ~/
   # expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the
   # destination user's data.
   #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u
 
   # Use the default namespace for saving subscriptions.
   #subscriptions = no
 
   # List the shared/ namespace only if there are visible shared mailboxes.
   #list = children
#}
 
# System user and group used to access mails. If you use multiple, userdb
# can override these by returning uid or gid fields. You can use either numbers
# or names. <doc/wiki/UserIds>
#mail_uid =
#mail_gid =
 
# Group to enable temporarily for privileged operations. Currently this is
# used only with INBOX when either its initial creation or dotlocking fails.
# Typically this is set to "mail" to give access to /var/mail.
#mail_privileged_group =
 
# Grant access to these supplementary groups for mail processes. Typically
# these are used to set up access to shared mailboxes. Note that it may be
# dangerous to set these if users can create symlinks (e.g. if "mail" group is
# set here, ln -s /var/mail ~/mail/var could allow a user to delete others'
# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).
#mail_access_groups =
 
# Allow full filesystem access to clients. There's no access checks other than
# what the operating system does for the active UID/GID. It works with both
# maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/
# or ~user/.
#mail_full_filesystem_access = no
 
##
## Mail processes
##
 
# Enable mail process debugging. This can help you figure out why Dovecot
# isn't finding your mails.
#mail_debug = no
 
# Log prefix for mail processes. See doc/wiki/Variables.txt for list of
# possible variables you can use.
#mail_log_prefix = "%Us(%u): "
 
# Max. number of lines a mail process is allowed to log per second before it's
# throttled. 0 means unlimited. Typically there's no need to change this
# unless you're using mail_log plugin, which may log a lot. This setting is
# ignored while mail_debug=yes to avoid pointless throttling.
#mail_log_max_lines_per_sec = 10
 
# Don't use mmap() at all. This is required if you store indexes to shared
# filesystems (NFS or clustered filesystem).
#mmap_disable = no
mmap_disable = yes
 
# Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL
# since version 3, so this should be safe to use nowadays by default.
#dotlock_use_excl = yes
 
# Don't use fsync() or fdatasync() calls. This makes the performance better
# at the cost of potential data loss if the server (or the file server)
# goes down.
#fsync_disable = no
 
# Mail storage exists in NFS. Set this to yes to make Dovecot flush NFS caches
# whenever needed. If you're using only a single mail server this isn't needed.
#mail_nfs_storage = no
mail_nfs_storage = yes
# Mail index files also exist in NFS. Setting this to yes requires
# mmap_disable=yes and fsync_disable=no.
#mail_nfs_index = no
mail_nfs_index = yes
 
# Locking method for index files. Alternatives are fcntl, flock and dotlock.
# Dotlocking uses some tricks which may create more disk I/O than other locking
# methods. NFS users: flock doesn't work, remember to change mmap_disable.
#lock_method = fcntl
 
# Drop all privileges before exec()ing the mail process. This is mostly
# meant for debugging, otherwise you don't get core dumps. It could be a small
# security risk if you use single UID for multiple users, as the users could
# ptrace() each others processes then.
#mail_drop_priv_before_exec = no
 
# Show more verbose process titles (in ps). Currently shows user name and
# IP address. Useful for seeing who are actually using the IMAP processes
# (eg. shared mailboxes or if same uid is used for multiple accounts).
#verbose_proctitle = no
 
# Valid UID range for users, defaults to 500 and above. This is mostly
# to make sure that users can't log in as daemons or other system users.
# Note that denying root logins is hardcoded to dovecot binary and can't
# be done even if first_valid_uid is set to 0.
#first_valid_uid = 500
#last_valid_uid = 0
 
# Valid GID range for users, defaults to non-root/wheel. Users having
# non-valid GID as primary group ID aren't allowed to log in. If user
# belongs to supplementary groups with non-valid GIDs, those groups are
# not set.
#first_valid_gid = 1
#last_valid_gid = 0
 
# Maximum number of running mail processes. When this limit is reached,
# new users aren't allowed to log in.
#max_mail_processes = 512
 
# Set max. process size in megabytes. Most of the memory goes to mmap()ing
# files, so it shouldn't harm much even if this limit is set pretty high.
#mail_process_size = 256
mail_process_size = 0
 
# Maximum allowed length for mail keyword name. It's only forced when trying
# to create new keywords.
#mail_max_keyword_length = 50
 
# ':' separated list of directories under which chrooting is allowed for mail
# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).
# This setting doesn't affect login_chroot, mail_chroot or auth chroot
# settings. If this setting is empty, "/./" in home dirs are ignored.
# WARNING: Never add directories here which local users can modify, that
# may lead to root exploit. Usually this should be done only if you don't
# allow shell access for users. <doc/wiki/Chrooting.txt>
#valid_chroot_dirs = 
 
# Default chroot directory for mail processes. This can be overridden for
# specific users in user database by giving /./ in user's home directory
# (eg. /home/./user chroots into /home). Note that usually there is no real
# need to do chrooting, Dovecot doesn't allow users to access files outside
# their mail directory anyway. If your home directories are prefixed with
# the chroot directory, append "/." to mail_chroot. <doc/wiki/Chrooting.txt>
#mail_chroot = 
 
##
## Mailbox handling optimizations
##
 
# The minimum number of mails in a mailbox before updates are done to cache
# file. This allows optimizing Dovecot's behavior to do less disk writes at
# the cost of more disk reads.
#mail_cache_min_mail_count = 0
 
# When IDLE command is running, mailbox is checked once in a while to see if
# there are any new mails or other changes. This setting defines the minimum
# time in seconds to wait between those checks. Dovecot can also use dnotify,
# inotify and kqueue to find out immediately when changes occur.
#mailbox_idle_check_interval = 30
 
# Save mails with CR+LF instead of plain LF. This makes sending those mails
# take less CPU, especially with sendfile() syscall with Linux and FreeBSD.
# But it also creates a bit more disk I/O which may just make it slower.
# Also note that if other software reads the mboxes/maildirs, they may handle
# the extra CRs wrong and cause problems.
#mail_save_crlf = no
 
##
## Maildir-specific settings
##
 
# By default LIST command returns all entries in maildir beginning with a dot.
# Enabling this option makes Dovecot return only entries which are directories.
# This is done by stat()ing each entry, so it causes more disk I/O.
# (For systems setting struct dirent->d_type, this check is free and it's
# done always regardless of this setting)
#maildir_stat_dirs = no
 
# When copying a message, do it with hard links whenever possible. This makes
# the performance much better, and it's unlikely to have any side effects.
#maildir_copy_with_hardlinks = yes
 
# When copying a message, try to preserve the base filename. Only if the
# destination mailbox already contains the same name (ie. the mail is being
# copied there twice), a new name is given. The destination filename check is
# done only by looking at dovecot-uidlist file, so if something outside
# Dovecot does similar filename preserving copies, you may run into problems.
# NOTE: This setting requires maildir_copy_with_hardlinks = yes to work.
#maildir_copy_preserve_filename = no
 
##
## mbox-specific settings
##
 
# Which locking methods to use for locking mbox. There are four available:
#  dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe
#           solution. If you want to use /var/mail/ like directory, the users
#           will need write access to that directory.
#  dotlock_try: Same as dotlock, but if it fails because of permissions or
#               because there isn't enough disk space, just skip it.
#  fcntl  : Use this if possible. Works with NFS too if lockd is used.
#  flock  : May not exist in all systems. Doesn't work with NFS.
#  lockf  : May not exist in all systems. Doesn't work with NFS.
#
# You can use multiple locking methods; if you do the order they're declared
# in is important to avoid deadlocks if other MTAs/MUAs are using multiple
# locking methods as well. Some operating systems don't allow using some of
# them simultaneously.
#mbox_read_locks = fcntl
#mbox_write_locks = fcntl
 
# Maximum time in seconds to wait for lock (all of them) before aborting.
#mbox_lock_timeout = 300
 
# If dotlock exists but the mailbox isn't modified in any way, override the
# lock file after this many seconds.
#mbox_dotlock_change_timeout = 120
 
# When mbox changes unexpectedly we have to fully read it to find out what
# changed. If the mbox is large this can take a long time. Since the change
# is usually just a newly appended mail, it'd be faster to simply read the
# new mails. If this setting is enabled, Dovecot does this but still safely
# fallbacks to re-reading the whole mbox file whenever something in mbox isn't
# how it's expected to be. The only real downside to this setting is that if
# some other MUA changes message flags, Dovecot doesn't notice it immediately.
# Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK 
# commands.
#mbox_dirty_syncs = yes
 
# Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE,
# EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored.
#mbox_very_dirty_syncs = no
 
# Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK
# commands and when closing the mailbox). This is especially useful for POP3
# where clients often delete all mails. The downside is that our changes
# aren't immediately visible to other MUAs.
#mbox_lazy_writes = yes
 
# If mbox size is smaller than this (in kilobytes), don't write index files.
# If an index file already exists it's still read, just not updated.
#mbox_min_index_size = 0
 
##
## dbox-specific settings
##
 
# Maximum dbox file size in kilobytes until it's rotated.
#dbox_rotate_size = 2048
 
# Minimum dbox file size in kilobytes before it's rotated
# (overrides dbox_rotate_days)
#dbox_rotate_min_size = 16
 
# Maximum dbox file age in days until it's rotated. Day always begins from
# midnight, so 1 = today, 2 = yesterday, etc. 0 = check disabled.
#dbox_rotate_days = 0
 
##
## IMAP specific settings
##
 
protocol imap {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/imap-login
 
  # IMAP executable location. Changing this allows you to execute other
  # binaries before the imap process is executed.
  #
  # This would write rawlogs into ~/dovecot.rawlog/ directory:
  #   mail_executable = /usr/libexec/dovecot/rawlog /usr/libexec/dovecot/imap
  #
  # This would attach gdb into the imap process and write backtraces into
  # /tmp/gdbhelper.* files:
  #   mail_executable = /usr/libexec/dovecot/gdbhelper /usr/libexec/dovecot/imap
  #
  #mail_executable = /usr/libexec/dovecot/imap
 
  # Maximum IMAP command line length in bytes. Some clients generate very long
  # command lines with huge mailboxes, so you may need to raise this if you get
  # "Too long argument" or "IMAP command line too large" errors often.
  #imap_max_line_length = 65536
 
  # Maximum number of IMAP connections allowed for a user from each IP address.
  # NOTE: The username is compared case-sensitively.
  #mail_max_userip_connections = 10
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/imap
 
  # IMAP logout format string:
  #  %i - total number of bytes read from client
  #  %o - total number of bytes sent to client
  #imap_logout_format = bytes=%i/%o
 
  # Override the IMAP CAPABILITY response.
  #imap_capability = 
 
  # ID field names and values to send to clients. Using * as the value makes
  # Dovecot use the default value. The following fields have default values
  # currently: name, version, os, os-version, support-url, support-email.
  #imap_id_send = 
 
  # ID fields sent by client to log. * means everything.
  #imap_id_log =
 
  # Workarounds for various client bugs:
  #   delay-newmail:
  #     Send EXISTS/RECENT new mail notifications only when replying to NOOP
  #     and CHECK commands. Some clients ignore them otherwise, for example OSX
  #     Mail (<v2.1). Outlook Express breaks more badly though, without this it
  #     may show user "Message no longer in server" errors. Note that OE6 still
  #     breaks even with this workaround if synchronization is set to
  #     "Headers Only".
  #   netscape-eoh:
  #     Netscape 4.x breaks if message headers don't end with the empty "end of
  #     headers" line. Normally all messages have this, but setting this
  #     workaround makes sure that Netscape never breaks by adding the line if
  #     it doesn't exist. This is done only for FETCH BODY[HEADER.FIELDS..]
  #     commands. Note that RFC says this shouldn't be done.
  #   tb-extra-mailbox-sep:
  #     With mbox storage a mailbox can contain either mails or submailboxes,
  #     but not both. Thunderbird separates these two by forcing server to
  #     accept '/' suffix in mailbox names in subscriptions list.
  # The list is space-separated.
  #imap_client_workarounds = 
  imap_client_workarounds = delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep
}
 
##
## POP3 specific settings
##
 
protocol pop3 {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/pop3-login
 
  # POP3 executable location. See IMAP's mail_executable above for examples
  # how this could be changed.
  #mail_executable = /usr/libexec/dovecot/pop3
 
  # Don't try to set mails non-recent or seen with POP3 sessions. This is
  # mostly intended to reduce disk I/O. With maildir it doesn't move files
  # from new/ to cur/, with mbox it doesn't write Status-header.
  #pop3_no_flag_updates = no
 
  # Support LAST command which exists in old POP3 specs, but has been removed
  # from new ones. Some clients still wish to use this though. Enabling this
  # makes RSET command clear all \Seen flags from messages.
  #pop3_enable_last = no
 
  # If mail has X-UIDL header, use it as the mail's UIDL.
  #pop3_reuse_xuidl = no
 
  # Keep the mailbox locked for the entire POP3 session.
  #pop3_lock_session = no
 
  # POP3 UIDL (unique mail identifier) format to use. You can use following
  # variables, along with the variable modifiers described in
  # doc/wiki/Variables.txt (e.g. %Uf for the filename in uppercase)
  #
  #  %v - Mailbox's IMAP UIDVALIDITY
  #  %u - Mail's IMAP UID
  #  %m - MD5 sum of the mailbox headers in hex (mbox only)
  #  %f - filename (maildir only)
  #
  # If you want UIDL compatibility with other POP3 servers, use:
  #  UW's ipop3d         : %08Xv%08Xu
  #  Courier             : %f or %v-%u (both might be used simultaneosly)
  #  Cyrus (<= 2.1.3)    : %u
  #  Cyrus (>= 2.1.4)    : %v.%u
  #  Dovecot v0.99.x     : %v.%u
  #  tpop3d              : %Mf
  #
  # Note that Outlook 2003 seems to have problems with %v.%u format which was
  # Dovecot's default, so if you're building a new server it would be a good
  # idea to change this. %08Xu%08Xv should be pretty fail-safe.
  #
  #pop3_uidl_format = %08Xu%08Xv
 
  # POP3 logout format string:
  #  %i - total number of bytes read from client
  #  %o - total number of bytes sent to client
  #  %t - number of TOP commands
  #  %p - number of bytes sent to client as a result of TOP command
  #  %r - number of RETR commands
  #  %b - number of bytes sent to client as a result of RETR command
  #  %d - number of deleted messages
  #  %m - number of messages (before deletion)
  #  %s - mailbox size in bytes (before deletion)
  #pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s
 
  # Maximum number of POP3 connections allowed for a user from each IP address.
  # NOTE: The username is compared case-sensitively.
  #mail_max_userip_connections = 3
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/pop3
 
  # Workarounds for various client bugs:
  #   outlook-no-nuls:
  #     Outlook and Outlook Express hang if mails contain NUL characters.
  #     This setting replaces them with 0x80 character.
  #   oe-ns-eoh:
  #     Outlook Express and Netscape Mail breaks if end of headers-line is
  #     missing. This option simply sends it if it's missing.
  # The list is space-separated.
  #pop3_client_workarounds = 
  pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
}
 
##
## MANAGESIEVE specific settings
##
 
protocol managesieve {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/managesieve-login
 
  # MANAGESIEVE executable location. See IMAP's mail_executable above for 
  # examples how this could be changed.
  #mail_executable = /usr/libexec/dovecot/managesieve
 
  # Maximum MANAGESIEVE command line length in bytes. This setting is 
  # directly borrowed from IMAP. But, since long command lines are very
  # unlikely with MANAGESIEVE, changing this will not be very useful.  
  #managesieve_max_line_length = 65536
 
  # If, for some inobvious reason, the sieve_storage remains unset, the 
  # managesieve daemon uses the specification of the mail_location to find out 
  # where to store the sieve files (see explaination in README.managesieve). 
  # The example below, when uncommented, overrides any global mail_location 
  # specification and stores all the scripts in '~/mail/sieve' if sieve_storage 
  # is unset. However, you should always use the sieve_storage setting.
  # mail_location = mbox:~/mail
 
  # To fool managesieve clients that are focused on timesieved you can
  # specify the IMPLEMENTATION capability that the dovecot reports to clients 
  # (default: dovecot).
  #managesieve_implementation_string = Cyrus timsieved v2.2.13
}
 
##
## LDA specific settings
##
 
protocol lda {
  # Address to use when sending rejection mails.
  postmaster_address = postmaster@example.com
 
  # Hostname to use in various parts of sent mails, eg. in Message-Id.
  # Default is the system's real hostname.
  #hostname = 
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/lda
 
  # If user is over quota, return with temporary failure instead of
  # bouncing the mail.
  #quota_full_tempfail = no
 
  # Format to use for logging mail deliveries. You can use variables:
  #  %$ - Delivery status message (e.g. "saved to INBOX")
  #  %m - Message-ID
  #  %s - Subject
  #  %f - From address
  #deliver_log_format = msgid=%m: %$
 
  # Binary to use for sending mails.
  #sendmail_path = /usr/lib/sendmail
 
  # Subject: header to use for rejection mails. You can use the same variables
  # as for rejection_reason below.
  #rejection_subject = Rejected: %s
 
  # Human readable error message for rejection mails. You can use variables:
  #  %n = CRLF, %r = reason, %s = original subject, %t = recipient
  #rejection_reason = Your message to <%t> was automatically rejected:%n%r
 
  # UNIX socket path to master authentication server to find users.
  #auth_socket_path = /var/run/dovecot/auth-master
}
 
##
## Authentication processes
##
 
# Executable location
#auth_executable = /usr/libexec/dovecot/dovecot-auth
 
# Set max. process size in megabytes.
#auth_process_size = 256
 
# Authentication cache size in kilobytes. 0 means it's disabled.
# Note that bsdauth, PAM and vpopmail require cache_key to be set for caching
# to be used.
#auth_cache_size = 0
# Time to live in seconds for cached data. After this many seconds the cached
# record is no longer used, *except* if the main database lookup returns
# internal failure. We also try to handle password changes automatically: If
# user's previous authentication was successful, but this one wasn't, the
# cache isn't used. For now this works only with plaintext authentication.
#auth_cache_ttl = 3600
# TTL for negative hits (user not found). 0 disables caching them completely.
#auth_cache_negative_ttl = 3600
 
# Space separated list of realms for SASL authentication mechanisms that need
# them. You can leave it empty if you don't want to support multiple realms.
# Many clients simply use the first one listed here, so keep the default realm
# first.
#auth_realms =
 
# Default realm/domain to use if none was specified. This is used for both
# SASL realms and appending @domain to username in plaintext logins.
#auth_default_realm = 
 
# List of allowed characters in username. If the user-given username contains
# a character not listed in here, the login automatically fails. This is just
# an extra check to make sure user can't exploit any potential quote escaping
# vulnerabilities with SQL/LDAP databases. If you want to allow all characters,
# set this value to empty.
#auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@
 
# Username character translations before it's looked up from databases. The
# value contains series of from -> to characters. For example "#@/@" means
# that '#' and '/' characters are translated to '@'.
#auth_username_translation =
 
# Username formatting before it's looked up from databases. You can use
# the standard variables here, eg. %Lu would lowercase the username, %n would
# drop away the domain if it was given, or "%n-AT-%d" would change the '@' into
# "-AT-". This translation is done after auth_username_translation changes.
#auth_username_format =
 
# If you want to allow master users to log in by specifying the master
# username within the normal username string (ie. not using SASL mechanism's
# support for it), you can specify the separator character here. The format
# is then <username><separator><master username>. UW-IMAP uses "*" as the
# separator, so that could be a good choice.
#auth_master_user_separator =
 
# Username to use for users logging in with ANONYMOUS SASL mechanism
#auth_anonymous_username = anonymous
 
# More verbose logging. Useful for figuring out why authentication isn't
# working.
#auth_verbose = no
 
# Even more verbose logging for debugging purposes. Shows for example SQL
# queries.
#auth_debug = no
 
# In case of password mismatches, log the passwords and used scheme so the
# problem can be debugged. Enabling this also enables auth_debug.
#auth_debug_passwords = no
 
# Maximum number of dovecot-auth worker processes. They're used to execute
# blocking passdb and userdb queries (eg. MySQL and PAM). They're
# automatically created and destroyed as needed.
#auth_worker_max_count = 30
 
# Host name to use in GSSAPI principal names. The default is to use the
# name returned by gethostname(). Use "$ALL" to allow all keytab entries.
#auth_gssapi_hostname =
 
# Kerberos keytab to use for the GSSAPI mechanism. Will use the system 
# default (usually /etc/krb5.keytab) if not specified.
#auth_krb5_keytab = 
 
# Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon and
# ntlm_auth helper. <doc/wiki/Authentication/Mechanisms/Winbind.txt>
#auth_use_winbind = no
 
# Path for Samba's ntlm_auth helper binary.
#auth_winbind_helper_path = /usr/bin/ntlm_auth
 
# Number of seconds to delay before replying to failed authentications.
#auth_failure_delay = 2
 
auth default {
  # Space separated list of wanted authentication mechanisms:
  #   plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi otp skey
  #   gss-spnego
  # NOTE: See also disable_plaintext_auth setting.
  mechanisms = plain
 
  #
  # Password database is used to verify user's password (and nothing more).
  # You can have multiple passdbs and userdbs. This is useful if you want to
  # allow both system users (/etc/passwd) and virtual users to login without
  # duplicating the system users into virtual database.
  #
  # <doc/wiki/PasswordDatabase.txt>
  #
  # By adding master=yes setting inside a passdb you make the passdb a list
  # of "master users", who can log in as anyone else. Unless you're using PAM,
  # you probably still want the destination user to be looked up from passdb
  # that it really exists. This can be done by adding pass=yes setting to the
  # master passdb. <doc/wiki/Authentication.MasterUsers.txt>
 
  # Users can be temporarily disabled by adding a passdb with deny=yes.
  # If the user is found from that database, authentication will fail.
  # The deny passdb should always be specified before others, so it gets
  # checked first. Here's an example:
 
  #passdb passwd-file {
    # File contains a list of usernames, one per line
    #args = /etc/dovecot.deny
    #deny = yes
  #}
 
  # PAM authentication. Preferred nowadays by most systems. 
  # Note that PAM can only be used to verify if user's password is correct,
  # so it can't be used as userdb. If you don't want to use a separate user
  # database (passwd usually), you can use static userdb.
  # REMEMBER: You'll need /etc/pam.d/dovecot file created for PAM
  # authentication to actually work. <doc/wiki/PasswordDatabase.PAM.txt>
  passdb pam {
    # [session=yes] [setcred=yes] [failure_show_msg=yes] [max_requests=<n>]
    # [cache_key=<key>] [<service name>]
    #
    # session=yes makes Dovecot open and immediately close PAM session. Some
    # PAM plugins need this to work, such as pam_mkhomedir.
    #
    # setcred=yes makes Dovecot establish PAM credentials if some PAM plugins
    # need that. They aren't ever deleted though, so this isn't enabled by
    # default.
    #
    # max_requests specifies how many PAM lookups to do in one process before
    # recreating the process. The default is 100, because many PAM plugins
    # leak memory.
    #
    # cache_key can be used to enable authentication caching for PAM
    # (auth_cache_size also needs to be set). It isn't enabled by default
    # because PAM modules can do all kinds of checks besides checking password,
    # such as checking IP address. Dovecot can't know about these checks
    # without some help. cache_key is simply a list of variables (see
    # doc/wiki/Variables.txt) which must match for the cached data to be used.
    # Here are some examples:
    #   %u - Username must match. Probably sufficient for most uses.
    #   %u%r - Username and remote IP address must match.
    #   %u%s - Username and service (ie. IMAP, POP3) must match.
    # 
    # The service name can contain variables, for example %Ls expands to
    # pop3 or imap.
    #
    # Some examples:
    #   args = session=yes %Ls
    #   args = cache_key=%u dovecot
    #args = dovecot
  }
 
  # System users (NSS, /etc/passwd, or similiar)
  # In many systems nowadays this uses Name Service Switch, which is
  # configured in /etc/nsswitch.conf. <doc/wiki/AuthDatabase.Passwd.txt>
  #passdb passwd {
    # [blocking=yes] - See userdb passwd for explanation
    #args = 
  #}
 
  # Shadow passwords for system users (NSS, /etc/shadow or similiar).
  # Deprecated by PAM nowadays.
  # <doc/wiki/PasswordDatabase.Shadow.txt>
  #passdb shadow {
    # [blocking=yes] - See userdb passwd for explanation
    #args = 
  #}
 
  # PAM-like authentication for OpenBSD.
  # <doc/wiki/PasswordDatabase.BSDAuth.txt>
  #passdb bsdauth {
    # [cache_key=<key>] - See cache_key in PAM for explanation.
    #args =
  #}
 
  # passwd-like file with specified location
  # <doc/wiki/AuthDatabase.PasswdFile.txt>
  #passdb passwd-file {
    # [scheme=<default password scheme>] [username_format=<format>]
    # <Path for passwd-file>
    #args = 
  #}
 
  # checkpassword executable authentication
  # NOTE: You will probably want to use "userdb prefetch" with this.
  # <doc/wiki/AuthDatabase.CheckPassword.txt>
  #passdb checkpassword {
    # Path for checkpassword binary
    #args = 
  #}
 
  # SQL database <doc/wiki/AuthDatabase.SQL.txt>
  #passdb sql {
    # Path for SQL configuration file, see doc/dovecot-sql-example.conf
    #args = 
  #}
 
  # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
  #passdb ldap {
    # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
    #args = 
  #}
 
  # vpopmail authentication <doc/wiki/AuthDatabase.VPopMail.txt>
  #passdb vpopmail {
    # [cache_key=<key>] - See cache_key in PAM for explanation.
    # [quota_template=<template>] - %q expands to Maildir++ quota
    #   (eg. quota_template=quota_rule=*:backend=%q)
    #args =
  #}
 
  #
  # User database specifies where mails are located and what user/group IDs
  # own them. For single-UID configuration use "static".
  #
  # <doc/wiki/UserDatabase.txt>
  #
 
  # "prefetch" user database means that the passdb already provided the
  # needed information and there's no need to do a separate userdb lookup.
  # This can be made to work with SQL and LDAP databases, see their example
  # configuration files for more information how to do it.
  # <doc/wiki/UserDatabase.Prefetch.txt>
  #userdb prefetch {
  #}
 
  # System users (NSS, /etc/passwd, or similiar). In many systems nowadays this
  # uses Name Service Switch, which is configured in /etc/nsswitch.conf.
  # <doc/wiki/AuthDatabase.Passwd.txt>
  userdb passwd {
    # [blocking=yes] - By default the lookups are done in the main dovecot-auth
    # process. This setting causes the lookups to be done in auth worker
    # proceses. Useful with remote NSS lookups that may block.
    # NOTE: Be sure to use this setting with nss_ldap or users might get
    # logged in as each others!
    #args = 
  }
 
  # passwd-like file with specified location
  # <doc/wiki/AuthDatabase.PasswdFile.txt>
  #userdb passwd-file {
    # [username_format=<format>] <Path for passwd-file>
    #args =
  #}
 
  # checkpassword executable user database lookup
  # <doc/wiki/AuthDatabase.CheckPassword.txt>
  #userdb checkpassword {
    # Path for checkpassword binary
    #args = 
  #}
 
  # static settings generated from template <doc/wiki/UserDatabase.Static.txt>
  #userdb static {
    # Template for the fields. Can return anything a userdb could normally
    # return. For example:
    #
    #  args = uid=500 gid=500 home=/var/mail/%u
    #
    # If you use deliver, it needs to look up users only from the userdb. This
    # of course doesn't work with static because there is no list of users.
    # Normally static userdb handles this by doing a passdb lookup. This works
    # with most passdbs, with PAM being the most notable exception. If you do
    # the user verification another way, you can add allow_all_users=yes to
    # the args in which case the passdb lookup is skipped.
    #
    #args =
  #}
 
  # SQL database <doc/wiki/AuthDatabase.SQL.txt>
  #userdb sql {
    # Path for SQL configuration file, see doc/dovecot-sql-example.conf
    #args = 
  #}
 
  # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
  #userdb ldap {
    # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
    #args = 
  #}
 
  # vpopmail <doc/wiki/AuthDatabase.VPopMail.txt>
  #userdb vpopmail {
  #}
 
  # User to use for the process. This user needs access to only user and
  # password databases, nothing else. Only shadow and pam authentication
  # requires roots, so use something else if possible. Note that passwd
  # authentication with BSDs internally accesses shadow files, which also
  # requires roots. Note that this user is NOT used to access mails.
  # That user is specified by userdb above.
  user = root
 
  # Directory where to chroot the process. Most authentication backends don't
  # work if this is set, and there's no point chrooting if auth_user is root.
  # Note that valid_chroot_dirs isn't needed to use this setting.
  #chroot = 
 
  # Number of authentication processes to create
  #count = 1
 
  # Require a valid SSL client certificate or the authentication fails.
  #ssl_require_client_cert = no
 
  # Take the username from client's SSL certificate, using 
  # X509_NAME_get_text_by_NID() which returns the subject's DN's
  # CommonName. 
  #ssl_username_from_cert = no
 
  # It's possible to export the authentication interface to other programs:
  #socket listen {
    #master {
      # Master socket provides access to userdb information. It's typically
      # used to give Dovecot's local delivery agent access to userdb so it
      # can find mailbox locations.
      #path = /var/run/dovecot/auth-master
      #mode = 0600
      # Default user/group is the one who started dovecot-auth (root)
      #user = 
      #group = 
    #}
    #client {
      # The client socket is generally safe to export to everyone. Typical use
      # is to export it to your SMTP server so it can do SMTP AUTH lookups
      # using it.
      #path = /var/run/dovecot/auth-client
      #mode = 0660
    #}
  #}
}
 
# If you wish to use another authentication server than dovecot-auth, you can
# use connect sockets. They are assumed to be already running, Dovecot's master
# process only tries to connect to them. They don't need any other settings
# than the path for the master socket, as the configuration is done elsewhere.
# Note that the client sockets must exist in the login_dir.
#auth external {
#  socket connect {
#    master {
#      path = /var/run/dovecot/auth-master
#    }
#  }
#}
 
##
## Dictionary server settings
##
 
# Dictionary can be used by some plugins to store key=value lists.
# Currently this is only used by dict quota backend. The dictionary can be
# used either directly or though a dictionary server. The following dict block
# maps dictionary names to URIs when the server is used. These can then be
# referenced using URIs in format "proxy::<name>".
 
dict {
  #quota = mysql:/etc/dovecot-dict-quota.conf 
  #expire = db:/var/lib/dovecot/expire.db
}
 
# Path to Berkeley DB's configuration file. See doc/dovecot-db-example.conf
#dict_db_config = 
 
##
## Plugin settings
##
 
plugin {
  # Here you can give some extra environment variables to mail processes.
  # This is mostly meant for passing parameters to plugins. %variable
  # expansion is done for all values.
 
  # Quota plugin. Multiple backends are supported:
  #   dirsize: Find and sum all the files found from mail directory.
  #            Extremely SLOW with Maildir. It'll eat your CPU and disk I/O.
  #   dict: Keep quota stored in dictionary (eg. SQL)
  #   maildir: Maildir++ quota
  #   fs: Read-only support for filesystem quota
  #
  # Quota limits are set using "quota_rule" parameters, either in here or in
  # userdb. It's also possible to give mailbox-specific limits, for example:
  #   quota_rule = *:storage=1048576
  #   quota_rule2 = Trash:storage=102400
  # User has now 1GB quota, but when saving to Trash mailbox the user gets
  # additional 100MB.
  #
  # Multiple quota roots are also possible, for example:
  #   quota = dict:user::proxy::quota
  #   quota2 = dict:domain:%d:proxy::quota_domain
  #   quota_rule = *:storage=102400
  #   quota2_rule = *:storage=1048576
  # Gives each user their own 100MB quota and one shared 1GB quota within
  # the domain.
  #
  # You can execute a given command when user exceeds a specified quota limit.
  # Each quota root has separate limits. Only the command for the first
  # exceeded limit is excecuted, so put the highest limit first.
  # Note that % needs to be escaped as %%, otherwise "% " expands to empty.
  #   quota_warning = storage=95%% /usr/local/bin/quota-warning.sh 95
  #   quota_warning2 = storage=80%% /usr/local/bin/quota-warning.sh 80
  #quota = maildir
 
  # ACL plugin. vfile backend reads ACLs from "dovecot-acl" file from maildir
  # directory. You can also optionally give a global ACL directory path where
  # ACLs are applied to all users' mailboxes. The global ACL directory contains
  # one file for each mailbox, eg. INBOX or sub.mailbox. cache_secs parameter
  # specifies how many seconds to wait between stat()ing dovecot-acl file
  # to see if it changed.
  #acl = vfile:/etc/dovecot-acls:cache_secs=300
 
  # To let users LIST mailboxes shared by other users, Dovecot needs a
  # shared mailbox dictionary. For example:
  #acl_shared_dict = file:/var/lib/dovecot/shared-mailboxes
 
  # Convert plugin. If set, specifies the source storage path which is
  # converted to destination storage (mail_location) when the user logs in.
  # The existing mail directory is renamed to <dir>-converted.
  #convert_mail = mbox:%h/mail
  # Skip mailboxes which we can't open successfully instead of aborting.
  #convert_skip_broken_mailboxes = no
  # Skip directories beginning with '.'
  #convert_skip_dotdirs = no
  # If source storage has mailbox names with destination storage's hierarchy
  # separators, replace them with this character.
  #convert_alt_hierarchy_char = _
 
  # Trash plugin. When saving a message would make user go over quota, this
  # plugin automatically deletes the oldest mails from configured mailboxes
  # until the message can be saved within quota limits. The configuration file
  # is a text file where each line is in format: <priority> <mailbox name>
  # Mails are first deleted in lowest -> highest priority number order
  #trash = /etc/dovecot-trash.conf
 
  # Expire plugin. Mails are expunged from mailboxes after being there the
  # configurable time. The first expiration date for each mailbox is stored in
  # a dictionary so it can be quickly determined which mailboxes contain
  # expired mails. The actual expunging is done in a nightly cronjob, which
  # you must set up:
  #   dovecot --exec-mail ext /usr/libexec/dovecot/expire-tool
  #expire = Trash 7 Spam 30
  #expire_dict = proxy::expire
 
  # Lazy expunge plugin. Currently works only with maildirs. When a user
  # expunges mails, the mails are moved to a mailbox in another namespace
  # (1st). When a mailbox is deleted, the mailbox is moved to another namespace
  # (2nd) as well. Also if the deleted mailbox had any expunged messages,
  # they're moved to a 3rd namespace. The mails won't be counted in quota,
  # and they're not deleted automatically (use a cronjob or something).
  #lazy_expunge = .EXPUNGED/ .DELETED/ .DELETED/.EXPUNGED/
 
  # Events to log. Also available: flag_change append
  #mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename
  # Group events within a transaction to one line.
  #mail_log_group_events = 
  # Available fields: uid, box, msgid, from, subject, size, vsize, flags
  # size and vsize are available only for expunge and copy events.
  #mail_log_fields = uid box msgid size
 
  # Sieve plugin (http://wiki.dovecot.org/LDA/Sieve) and ManageSieve service
  # 
  # Location of the active script. When ManageSieve is used this is actually 
  # a symlink pointing to the active script in the sieve storage directory. 
  #sieve=~/.dovecot.sieve
  #
  # The path to the directory where the personal Sieve scripts are stored. For 
  # ManageSieve this is where the uploaded scripts are stored.
  #sieve_dir=~/sieve
}

Optional Extras

Setting up SPF

Method 1: use the C based SPF milter, “smf-spf”

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yum install smf-spf

Add the following to sendmail.mc and re-make sendmail.cf

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dnl **
dnl ** enable smf-spf (Sender Policy Framework) **
dnl **
define(`confMILTER_MACROS_HELO', confMILTER_MACROS_HELO`, {verify}')dnl
INPUT_MAIL_FILTER(`smf-spf', `S=unix:/var/run/smfs/smf-spf.sock, T=S:30s;R:1m')dnl

Starting it up

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/etc/init.d/smf-spf restart
/etc/init.d/sendmail restart

Don’t forget to run chkconfig if you want to make smf-spf start up permanentally between reboots.h5. Setting up ClamAV

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yum install clamav \
 clamav-db \
 clamav-milter \
 clamd

Setup /etc/sysconfig/clamav-milter

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### Simple config file for clamav-milter, you should
### read the documentation and tweak it as you wish.
 
CLAMAV_FLAGS="--config-file=/etc/clamav-milter.conf"

Setup /etc/clamav-milter.conf

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##
## Example config file for clamav-milter
##
 
# Comment or remove the line below.
#Example
 
 
##
## Main options
##
 
# Define the interface through which we communicate with sendmail
# This option is mandatory! Possible formats are:
# [[unix|local]:]/path/to/file - to specify a unix domain socket
# inet:port@[hostname|ip-address] - to specify an ipv4 socket
# inet6:port@[hostname|ip-address] - to specify an ipv6 socket
#
# Default: no default
MilterSocket unix:/var/clamav/clmilter.socket
#MilterSocket inet:7357
 
# Remove stale socket after unclean shutdown.
#
# Default: yes
#FixStaleSocket yes
 
# Run as another user (clamav-milter must be started by root for this option to work)
#
# Default: unset (don't drop privileges)
User clamav
 
# Initialize supplementary group access (clamav-milter must be started by root).
#
# Default: no
AllowSupplementaryGroups yes
 
# Waiting for data from clamd will timeout after this time (seconds).
# Value of 0 disables the timeout.
#
# Default: 120
#ReadTimeout 300
 
# Don't fork into background.
#
# Default: no
#Foreground yes
 
# Chroot to the specified directory.
# Chrooting is performed just after reading the config file and before dropping privileges.
#
# Default: unset (don't chroot)
#Chroot /newroot
 
# This option allows you to save a process identifier of the listening
# daemon (main thread).
#
# Default: disabled
#PidFile /var/run/clamav-milter.pid
 
# Optional path to the global temporary directory.
# Default: system specific (usually /tmp or /var/tmp).
#
#TemporaryDirectory /var/tmp
 
##
## Clamd options
##
 
# Define the clamd socket to connect to for scanning.
# This option is mandatory! Syntax:
# ClamdSocket unix:path
# ClamdSocket tcp:host:port
# The first syntax specifies a local unix socket (needs an absolute path) e.g.:
#     ClamdSocket unix:/var/run/clamd/clamd.socket
# The second syntax specifies a tcp local or remote tcp socket: the
# host can be a hostname or an ip address; the ":port" field is only required
# for IPv6 addresses, otherwise it defaults to 3310
#     ClamdSocket tcp:192.168.0.1
#
# This option can be repeated several times with different sockets or even
# with the same socket: clamd servers will be selected in a round-robin fashion.
#
# Default: no default
ClamdSocket unix:/var/run/clamav/clamd.sock
 
 
##
## Exclusions
##
 
# Messages originating from these hosts/networks will not be scanned
# This option takes a host(name)/mask pair in CIRD notation and can be
# repeated several times. If "/mask" is omitted, a host is assumed.
# To specify a locally orignated, non-smtp, email use the keyword "local"
#
# Default: unset (scan everything regardless of the origin)
#LocalNet local
#LocalNet 192.168.0.0/24
#LocalNet 1111:2222:3333::/48
 
# This option specifies a file which contains a list of basic POSIX regular
# expressions. Addresses (sent to or from - see below) matching these regexes
# will not be scanned.  Optionally each line can start with the string "From:"
# or "To:" (note: no whitespace after the colon) indicating if it is, 
# respectively, the sender or recipient that is to be whitelisted.
# If the field is missing, "To:" is assumed.
# Lines starting with #, : or ! are ignored.
#
# Default unset (no exclusion applied)
#Whitelist /etc/whitelisted_addresses
 
# Messages from authenticated SMTP users matching this extended POSIX
# regular expression (egrep-like) will not be scanned.
# Note: this is the AUTH login name!
#
# Default: unset (no whitelisting based on SMTP auth)
#SkipAuthenticated ^(tom|dick|henry)$
 
 
##
## Actions
##
 
# The following group of options controls the delievery process under
# different circumstances.
# The following actions are available:
# - Accept
#   The message is accepted for delievery
# - Reject
#   Immediately refuse delievery (a 5xx error is returned to the peer)
# - Defer
#   Return a temporary failure message (4xx) to the peer
# - Blackhole (not available for OnFail)
#   Like accept but the message is sent to oblivion
# - Quarantine (not available for OnFail)
#   Like accept but message is quarantined instead of being delivered
#   In sendmail the quarantine queue can be examined via mailq -qQ
#   For Postfix this causes the message to be accepted but placed on hold
# 
# Action to be performed on clean messages (mostly useful for testing)
# Default Accept
#OnClean Accept
 
# Action to be performed on infected messages
# Default: Quarantine
#OnInfected Quarantine
 
# Action to be performed on error conditions (this includes failure to
# allocate data structures, no scanners available, network timeouts,
# unknown scanner replies and the like)
# Default Defer
#OnFail Defer
 
# This option allows to set a specific rejection reason for infected messages
# and it's therefore only useful together with "OnInfected Reject"
# The string "%v", if present, will be replaced with the virus name.
# Default: MTA specific
#RejectMsg 
 
# If this option is set to Yes, an "X-Virus-Scanned" and an "X-Virus-Status"
# headers will be attached to each processed message, possibly replacing
# existing headers. 
# Default: No
#AddHeader Yes
 
 
##
## Logging options
##
 
# Uncomment this option to enable logging.
# LogFile must be writable for the user running daemon.
# A full path is required.
#
# Default: disabled
LogFile /var/log/clamav/clamav-milter.log
 
# By default the log file is locked for writing - the lock protects against
# running clamav-milter multiple times.
# This option disables log file locking.
#
# Default: no
#LogFileUnlock yes
 
# Maximum size of the log file.
# Value of 0 disables the limit.
# You may use 'M' or 'm' for megabytes (1M = 1m = 1048576 bytes)
# and 'K' or 'k' for kilobytes (1K = 1k = 1024 bytes). To specify the size
# in bytes just don't use modifiers.
#
# Default: 1M
LogFileMaxSize 0
 
# Log time with each message.
#
# Default: no
LogTime yes
 
# Use system logger (can work together with LogFile).
#
# Default: no
LogSyslog yes
 
# Specify the type of syslog messages - please refer to 'man syslog'
# for facility names.
#
# Default: LOG_LOCAL6
#LogFacility LOG_MAIL
 
# Enable verbose logging.
#
# Default: no
#LogVerbose yes
 
# This option allows to tune what is logged when a message is infected.
# Possible values are Off (the default - nothing is logged),
# Basic (minimal info logged), Full (verbose info logged)
#
# Default: disabled
#LogInfected Basic
 
 
##
## Limits
##
 
# Messages larger than this value won't be scanned.
# Make sure this value is lower or equal than StreamMaxLength in clamd.conf
#
# Default: 25M
#MaxFileSize 10M

Setup /etc/clamd.conf

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##
## Example config file for the Clam AV daemon
## Please read the clamd.conf(5) manual before editing this file.
##
 
 
# Comment or remove the line below.
#Example
 
# Uncomment this option to enable logging.
# LogFile must be writable for the user running daemon.
# A full path is required.
# Default: disabled
LogFile /var/log/clamav/clamd.log
 
# By default the log file is locked for writing - the lock protects against
# running clamd multiple times (if want to run another clamd, please
# copy the configuration file, change the LogFile variable, and run
# the daemon with --config-file option).
# This option disables log file locking.
# Default: no
#LogFileUnlock yes
 
# Maximum size of the log file.
# Value of 0 disables the limit.
# You may use 'M' or 'm' for megabytes (1M = 1m = 1048576 bytes)
# and 'K' or 'k' for kilobytes (1K = 1k = 1024 bytes). To specify the size
# in bytes just don't use modifiers.
# Default: 1M
LogFileMaxSize 0
 
# Log time with each message.
# Default: no
LogTime yes
 
# Also log clean files. Useful in debugging but drastically increases the
# log size.
# Default: no
#LogClean yes
 
# Use system logger (can work together with LogFile).
# Default: no
LogSyslog yes
 
# Specify the type of syslog messages - please refer to 'man syslog'
# for facility names.
# Default: LOG_LOCAL6
#LogFacility LOG_MAIL
 
# Enable verbose logging.
# Default: no
#LogVerbose yes
 
# This option allows you to save a process identifier of the listening
# daemon (main thread).
# Default: disabled
PidFile /var/run/clamav/clamd.pid
 
# Optional path to the global temporary directory.
# Default: system specific (usually /tmp or /var/tmp).
TemporaryDirectory /var/tmp
 
# Path to the database directory.
# Default: hardcoded (depends on installation options)
DatabaseDirectory /var/clamav
 
# The daemon can work in local mode, network mode or both. 
# Due to security reasons we recommend the local mode.
 
# Path to a local socket file the daemon will listen on.
# Default: disabled (must be specified by a user)
LocalSocket /var/run/clamav/clamd.sock
 
# Remove stale socket after unclean shutdown.
# Default: yes
FixStaleSocket yes
 
# TCP port address.
# Default: no
TCPSocket 3310
 
# TCP address.
# By default we bind to INADDR_ANY, probably not wise.
# Enable the following to provide some degree of protection
# from the outside world.
# Default: no
TCPAddr 127.0.0.1
 
# Maximum length the queue of pending connections may grow to.
# Default: 15
MaxConnectionQueueLength 30
 
# Clamd uses FTP-like protocol to receive data from remote clients.
# If you are using clamav-milter to balance load between remote clamd daemons
# on firewall servers you may need to tune the options below.
 
# Close the connection when the data size limit is exceeded.
# The value should match your MTA's limit for a maximum attachment size.
# Default: 25M
#StreamMaxLength 10M
 
# Limit port range.
# Default: 1024
#StreamMinPort 30000
# Default: 2048
#StreamMaxPort 32000
 
# Maximum number of threads running at the same time.
# Default: 10
MaxThreads 50
 
# Waiting for data from a client socket will timeout after this time (seconds).
# Value of 0 disables the timeout.
# Default: 120
ReadTimeout 300
 
# This option specifies the time (in seconds) after which clamd should
# timeout if a client doesn't provide any initial command after connecting.
# Default: 5
#CommandReadTimeout 5
 
# This option specifies how long to wait (in miliseconds) if the send buffer is full.
# Keep this value low to prevent clamd hanging
#
# Default: 500
#SendBufTimeout 200
 
# Maximum number of queued items (including those being processed by MaxThreads threads)
# It is recommended to have this value at least twice MaxThreads if possible.
# WARNING: you shouldn't increase this too much to avoid running out  of file descriptors,
# the following condition should hold:
# MaxThreads*MaxRecursion + (MaxQueue - MaxThreads) + 6< RLIMIT_NOFILE (usual max is 1024)
#
# Default: 100
#MaxQueue 200
 
# Waiting for a new job will timeout after this time (seconds).
# Default: 30
#IdleTimeout 60
 
# Don't scan files and directories matching regex
# This directive can be used multiple times
# Default: scan all
#ExcludePath ^/proc/
#ExcludePath ^/sys/
 
# Maximum depth directories are scanned at.
# Default: 15
#MaxDirectoryRecursion 20
 
# Follow directory symlinks.
# Default: no
#FollowDirectorySymlinks yes
 
# Follow regular file symlinks.
# Default: no
#FollowFileSymlinks yes
 
# Perform a database check.
# Default: 600 (10 min)
#SelfCheck 600
 
# Execute a command when virus is found. In the command string %v will
# be replaced with the virus name.
# Default: no
#VirusEvent /usr/local/bin/send_sms 123456789 "VIRUS ALERT: %v"
 
# Run as another user (clamd must be started by root for this option to work)
# Default: don't drop privileges
User clamav
 
# Initialize supplementary group access (clamd must be started by root).
# Default: no
AllowSupplementaryGroups yes
 
# Stop daemon when libclamav reports out of memory condition.
#ExitOnOOM yes
 
# Don't fork into background.
# Default: no
#Foreground yes
 
# Enable debug messages in libclamav.
# Default: no
#Debug yes
 
# Do not remove temporary files (for debug purposes).
# Default: no
#LeaveTemporaryFiles yes
 
# Detect Possibly Unwanted Applications.
# Default: no
#DetectPUA yes
 
# Exclude a specific PUA category. This directive can be used multiple times.
# See http://www.clamav.net/support/pua for the complete list of PUA
# categories.
# Default: Load all categories (if DetectPUA is activated)
#ExcludePUA NetTool
#ExcludePUA PWTool
 
# Only include a specific PUA category. This directive can be used multiple
# times.
# Default: Load all categories (if DetectPUA is activated)
#IncludePUA Spy
#IncludePUA Scanner
#IncludePUA RAT
 
# In some cases (eg. complex malware, exploits in graphic files, and others),
# ClamAV uses special algorithms to provide accurate detection. This option
# controls the algorithmic detection.
# Default: yes
#AlgorithmicDetection yes
 
 
##
## Executable files
##
 
# PE stands for Portable Executable - it's an executable file format used
# in all 32 and 64-bit versions of Windows operating systems. This option allows
# ClamAV to perform a deeper analysis of executable files and it's also
# required for decompression of popular executable packers such as UPX, FSG,
# and Petite.
# Default: yes
ScanPE yes
 
# Executable and Linking Format is a standard format for UN*X executables.
# This option allows you to control the scanning of ELF files.
# Default: yes
ScanELF yes
 
# With this option clamav will try to detect broken executables (both PE and
# ELF) and mark them as Broken.Executable.
# Default: no
DetectBrokenExecutables yes
 
 
##
## Documents
##
 
# This option enables scanning of OLE2 files, such as Microsoft Office
# documents and .msi files.
# Default: yes
ScanOLE2 yes
 
# This option enables scanning within PDF files.
# Default: yes
#ScanPDF yes
 
 
##
## Mail files
##
 
# Enable internal e-mail scanner.
# Default: yes
ScanMail yes
 
# If an email contains URLs ClamAV can download and scan them.
# WARNING: This option may open your system to a DoS attack.
#	   Never use it on loaded servers.
# Default: no
#MailFollowURLs no
 
# Scan RFC1341 messages split over many emails.
# You will need to periodically clean up $TemporaryDirectory/clamav-partial directory.
# WARNING: This option may open your system to a DoS attack.
#	   Never use it on loaded servers.
# Default: no
#ScanPartialMessages yes
 
 
# With this option enabled ClamAV will try to detect phishing attempts by using
# signatures.
# Default: yes
#PhishingSignatures yes
 
# Scan URLs found in mails for phishing attempts using heuristics.
# Default: yes
#PhishingScanURLs yes
 
# Always block SSL mismatches in URLs, even if the URL isn't in the database.
# This can lead to false positives.
#
# Default: no
#PhishingAlwaysBlockSSLMismatch no
 
# Always block cloaked URLs, even if URL isn't in database.
# This can lead to false positives.
#
# Default: no
#PhishingAlwaysBlockCloak no
 
# Allow heuristic match to take precedence.
# When enabled, if a heuristic scan (such as phishingScan) detects
# a possible virus/phish it will stop scan immediately. Recommended, saves CPU
# scan-time.
# When disabled, virus/phish detected by heuristic scans will be reported only at
# the end of a scan. If an archive contains both a heuristically detected
# virus/phish, and a real malware, the real malware will be reported
#
# Keep this disabled if you intend to handle "*.Heuristics.*" viruses 
# differently from "real" malware.
# If a non-heuristically-detected virus (signature-based) is found first, 
# the scan is interrupted immediately, regardless of this config option.
#
# Default: no
#HeuristicScanPrecedence yes
 
##
## Data Loss Prevention (DLP)
##
 
# Enable the DLP module
# Default: No
#StructuredDataDetection yes
 
# This option sets the lowest number of Credit Card numbers found in a file
# to generate a detect.
# Default: 3
#StructuredMinCreditCardCount 5
 
# This option sets the lowest number of Social Security Numbers found
# in a file to generate a detect.
# Default: 3
#StructuredMinSSNCount 5
 
# With this option enabled the DLP module will search for valid
# SSNs formatted as xxx-yy-zzzz
# Default: yes
#StructuredSSNFormatNormal yes
 
# With this option enabled the DLP module will search for valid
# SSNs formatted as xxxyyzzzz
# Default: no
#StructuredSSNFormatStripped yes
 
 
##
## HTML
##
 
# Perform HTML normalisation and decryption of MS Script Encoder code.
# Default: yes
#ScanHTML yes
 
 
##
## Archives
##
 
# ClamAV can scan within archives and compressed files.
# Default: yes
ScanArchive yes
 
# Mark encrypted archives as viruses (Encrypted.Zip, Encrypted.RAR).
# Default: no
ArchiveBlockEncrypted no
 
 
##
## Limits
##
 
# The options below protect your system against Denial of Service attacks
# using archive bombs.
 
# This option sets the maximum amount of data to be scanned for each input file.
# Archives and other containers are recursively extracted and scanned up to this
# value.
# Value of 0 disables the limit
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 100M
#MaxScanSize 150M
 
# Files larger than this limit won't be scanned. Affects the input file itself
# as well as files contained inside it (when the input file is an archive, a
# document or some other kind of container).
# Value of 0 disables the limit.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 25M
#MaxFileSize 30M
 
# Nested archives are scanned recursively, e.g. if a Zip archive contains a RAR
# file, all files within it will also be scanned. This options specifies how
# deeply the process should be continued.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Value of 0 disables the limit.
# Default: 16
#MaxRecursion 10
 
# Number of files to be scanned within an archive, a document, or any other
# container file.
# Value of 0 disables the limit.
# Note: disabling this limit or setting it too high may result in severe damage
# to the system.
# Default: 10000
#MaxFiles 15000
 
 
##
## Clamuko settings
## WARNING: This is experimental software. It is very likely it will hang
##	    up your system!!!
##
 
# Enable Clamuko. Dazuko (/dev/dazuko) must be configured and running.
# Default: no
#ClamukoScanOnAccess yes
 
# Set access mask for Clamuko.
# Default: no
#ClamukoScanOnOpen yes
#ClamukoScanOnClose yes
#ClamukoScanOnExec yes
 
# Set the include paths (all files inside them will be scanned). You can have
# multiple ClamukoIncludePath directives but each directory must be added
# in a seperate line.
# Default: disabled
#ClamukoIncludePath /home
#ClamukoIncludePath /students
 
# Set the exclude paths. All subdirectories are also excluded.
# Default: disabled
#ClamukoExcludePath /home/bofh
 
# Don't scan files larger than ClamukoMaxFileSize
# Value of 0 disables the limit.
# Default: 5M
#ClamukoMaxFileSize 10M
Setting up Dovecot
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yum install dovecot

Setup /etc/dovecot.conf

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## Dovecot configuration file
 
# If you're in a hurry, see http://wiki.dovecot.org/QuickConfiguration
 
# "dovecot -n" command gives a clean output of the changed settings. Use it
# instead of copy&pasting this file when posting to the Dovecot mailing list.
 
# '#' character and everything after it is treated as comments. Extra spaces
# and tabs are ignored. If you want to use either of these explicitly, put the
# value inside quotes, eg.: key = "# char and trailing whitespace  "
 
# Default values are shown for each setting, it's not required to uncomment
# any of the lines.
 
# Base directory where to store runtime data.
#base_dir = /var/run/dovecot/
 
# Protocols we want to be serving: imap imaps pop3 pop3s managesieve
# If you only want to use dovecot-auth, you can set this to "none".
#protocols = imap imaps pop3 pop3s
protocols = imap imaps pop3 pop3s
 
# A space separated list of IP or host addresses where to listen in for
# connections. "*" listens in all IPv4 interfaces. "[::]" listens in all IPv6
# interfaces. Use "*, [::]" for listening both IPv4 and IPv6.
#
# If you want to specify ports for each service, you will need to configure
# these settings inside the protocol imap/pop3/managesieve { ... } section, 
# so you can specify different ports for IMAP/POP3/MANAGESIEVE. For example:
#   protocol imap {
#     listen = *:10143
#     ssl_listen = *:10943
#     ..
#   }
#   protocol pop3 {
#     listen = *:10100
#     ..
#   }
#   protocol managesieve {
#     listen = *:12000
#     ..
#   }
#listen = *, [::]
 
# Disable LOGIN command and all other plaintext authentications unless
# SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
# matches the local IP (ie. you're connecting from the same computer), the
# connection is considered secure and plaintext authentication is allowed.
#disable_plaintext_auth = no
 
# Should all IMAP and POP3 processes be killed when Dovecot master process
# shuts down. Setting this to "no" means that Dovecot can be upgraded without
# forcing existing client connections to close (although that could also be
# a problem if the upgrade is eg. because of a security fix). This however
# means that after master process has died, the client processes can't write
# to log files anymore.
#shutdown_clients = yes
 
##
## Logging
##
 
# Log file to use for error messages, instead of sending them to syslog.
# /dev/stderr can be used to log into stderr.
#log_path = 
 
# Log file to use for informational and debug messages.
# Default is the same as log_path.
#info_log_path = 
 
# Prefix for each line written to log file. % codes are in strftime(3)
# format.
#log_timestamp = "%b %d %H:%M:%S "
 
# Syslog facility to use if you're logging to syslog. Usually if you don't
# want to use "mail", you'll use local0..local7. Also other standard
# facilities are supported.
#syslog_facility = mail
 
##
## SSL settings
##
 
# IP or host address where to listen in for SSL connections. Remember to also
# add imaps and/or pop3s to protocols setting. Defaults to same as "listen"
# setting if not specified.
#ssl_listen =
 
# SSL/TLS support: yes, no, required. <doc/wiki/SSL>
#ssl = yes
 
# PEM encoded X.509 SSL/TLS certificate and private key. They're opened before
# dropping root privileges, so keep the key file unreadable by anyone but
# root. Included doc/mkcert.sh can be used to easily generate self-signed
# certificate, just make sure to update the domains in dovecot-openssl.cnf
ssl_cert_file = /etc/pki/dovecot/certs/dovecot.pem
ssl_key_file = /etc/pki/dovecot/private/dovecot.pem
 
# If key file is password protected, give the password here. Alternatively
# give it when starting dovecot with -p parameter. Since this file is often
# world-readable, you may want to place this setting instead to a different
# root owned 0600 file by using !include_try <path>.
#ssl_key_password =
 
# File containing trusted SSL certificate authorities. Set this only if you
# intend to use ssl_verify_client_cert=yes. The CAfile should contain the
# CA-certificate(s) followed by the matching CRL(s).
#ssl_ca_file = 
 
# Request client to send a certificate. If you also want to require it, set
# ssl_require_client_cert=yes in auth section.
#ssl_verify_client_cert = no
 
# Which field from certificate to use for username. commonName and
# x500UniqueIdentifier are the usual choices. You'll also need to set
# ssl_username_from_cert=yes.
#ssl_cert_username_field = commonName
 
# How often to regenerate the SSL parameters file. Generation is quite CPU
# intensive operation. The value is in hours, 0 disables regeneration
# entirely.
#ssl_parameters_regenerate = 168
 
# SSL ciphers to use
#ssl_cipher_list = ALL:!LOW:!SSLv2
 
# Show protocol level SSL errors.
#verbose_ssl = no
 
##
## Login processes
##
 
# <doc/wiki/LoginProcess.txt>
 
# Directory where authentication process places authentication UNIX sockets
# which login needs to be able to connect to. The sockets are created when
# running as root, so you don't have to worry about permissions. Note that
# everything in this directory is deleted when Dovecot is started.
#login_dir = /var/run/dovecot/login
 
# chroot login process to the login_dir. Only reason not to do this is if you
# wish to run the whole Dovecot without roots. <doc/wiki/Rootless.txt>
#login_chroot = yes
 
# User to use for the login process. Create a completely new user for this,
# and don't use it anywhere else. The user must also belong to a group where
# only it has access, it's used to control access for authentication process.
# Note that this user is NOT used to access mails. <doc/wiki/UserIds.txt>
#login_user = dovecot
 
# Set max. process size in megabytes. If you don't use
# login_process_per_connection you might need to grow this.
#login_process_size = 64
 
# Should each login be processed in it's own process (yes), or should one
# login process be allowed to process multiple connections (no)? Yes is more
# secure, espcially with SSL/TLS enabled. No is faster since there's no need
# to create processes all the time.
#login_process_per_connection = yes
 
# Number of login processes to keep for listening new connections.
#login_processes_count = 3
 
# Maximum number of login processes to create. The listening process count
# usually stays at login_processes_count, but when multiple users start logging
# in at the same time more extra processes are created. To prevent fork-bombing
# we check only once in a second if new processes should be created - if all
# of them are used at the time, we double their amount until the limit set by
# this setting is reached.
#login_max_processes_count = 128
 
# Maximum number of connections allowed per each login process. This setting
# is used only if login_process_per_connection=no. Once the limit is reached,
# the process notifies master so that it can create a new login process.
#login_max_connections = 256
 
# Greeting message for clients.
#login_greeting = Dovecot ready.
 
# Space separated list of trusted network ranges. Connections from these
# IPs are allowed to override their IP addresses and ports (for logging and
# for authentication checks). disable_plaintext_auth is also ignored for
# these networks. Typically you'd specify your IMAP proxy servers here.
#login_trusted_networks =
 
# Space-separated list of elements we want to log. The elements which have
# a non-empty variable value are joined together to form a comma-separated
# string.
#login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c
 
# Login log format. %$ contains login_log_format_elements string, %s contains
# the data we want to log.
#login_log_format = %$: %s
 
##
## Mailbox locations and namespaces
##
 
# Location for users' mailboxes. This is the same as the old default_mail_env
# setting. The default is empty, which means that Dovecot tries to find the
# mailboxes automatically. This won't work if the user doesn't have any mail
# yet, so you should explicitly tell Dovecot the full location.
#
# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u)
# isn't enough. You'll also need to tell Dovecot where the other mailboxes are
# kept. This is called the "root mail directory", and it must be the first
# path given in the mail_location setting.
#
# There are a few special variables you can use, eg.:
#
#   %u - username
#   %n - user part in user@domain, same as %u if there's no domain
#   %d - domain part in user@domain, empty if there's no domain
#   %h - home directory
#
# See doc/wiki/Variables.txt for full list. Some examples:
#
#   mail_location = maildir:~/Maildir
#   mail_location = mbox:~/mail:INBOX=/var/mail/%u
#   mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
#
# <doc/wiki/MailLocation.txt>
#
#mail_location =
mail_location = mbox:~/Mail:INBOX=/home/%u/Mail/INBOX
 
# If you need to set multiple mailbox locations or want to change default
# namespace settings, you can do it by defining namespace sections.
#
# You can have private, shared and public namespaces. Private namespaces
# are for user's personal mails. Shared namespaces are for accessing other
# users' mailboxes that have been shared. Public namespaces are for shared
# mailboxes that are managed by sysadmin. If you create any shared or public
# namespaces you'll typically want to enable ACL plugin also, otherwise all
# users can access all the shared mailboxes, assuming they have permissions
# on filesystem level to do so.
#
# REMEMBER: If you add any namespaces, the default namespace must be added
# explicitly, ie. mail_location does nothing unless you have a namespace
# without a location setting. Default namespace is simply done by having a
# namespace with empty prefix.
#namespace private {
   # Hierarchy separator to use. You should use the same separator for all
   # namespaces or some clients get confused. '/' is usually a good one.
   # The default however depends on the underlying mail storage format.
   #separator = 
 
   # Prefix required to access this namespace. This needs to be different for
   # all namespaces. For example "Public/".
   #prefix = 
 
   # Physical location of the mailbox. This is in same format as
   # mail_location, which is also the default for it.
   #location =
 
   # There can be only one INBOX, and this setting defines which namespace
   # has it.
   #inbox = no
 
   # If namespace is hidden, it's not advertised to clients via NAMESPACE
   # extension. You'll most likely also want to set list=no. This is mostly
   # useful when converting from another server with different namespaces which
   # you want to deprecate but still keep working. For example you can create
   # hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/".
   #hidden = yes
 
   # Show the mailboxes under this namespace with LIST command. This makes the
   # namespace visible for clients that don't support NAMESPACE extension.
   # "children" value lists child mailboxes, but hides the namespace prefix.
   #list = yes
 
   # Namespace handles its own subscriptions. If set to "no", the parent
   # namespace handles them (empty prefix should always have this as "yes")
   #subscriptions = yes
#}
 
# Example shared namespace configuration
#namespace shared {
   #separator = /
 
   # Mailboxes are visible under "shared/user@domain/"
   # %%n, %%d and %%u are expanded to the destination user.
   #prefix = shared/%%u/
 
   # Mail location for other users' mailboxes. Note that %variables and ~/
   # expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the
   # destination user's data.
   #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u
 
   # Use the default namespace for saving subscriptions.
   #subscriptions = no
 
   # List the shared/ namespace only if there are visible shared mailboxes.
   #list = children
#}
 
# System user and group used to access mails. If you use multiple, userdb
# can override these by returning uid or gid fields. You can use either numbers
# or names. <doc/wiki/UserIds>
#mail_uid =
#mail_gid =
 
# Group to enable temporarily for privileged operations. Currently this is
# used only with INBOX when either its initial creation or dotlocking fails.
# Typically this is set to "mail" to give access to /var/mail.
#mail_privileged_group =
 
# Grant access to these supplementary groups for mail processes. Typically
# these are used to set up access to shared mailboxes. Note that it may be
# dangerous to set these if users can create symlinks (e.g. if "mail" group is
# set here, ln -s /var/mail ~/mail/var could allow a user to delete others'
# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).
#mail_access_groups =
 
# Allow full filesystem access to clients. There's no access checks other than
# what the operating system does for the active UID/GID. It works with both
# maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/
# or ~user/.
#mail_full_filesystem_access = no
 
##
## Mail processes
##
 
# Enable mail process debugging. This can help you figure out why Dovecot
# isn't finding your mails.
#mail_debug = no
 
# Log prefix for mail processes. See doc/wiki/Variables.txt for list of
# possible variables you can use.
#mail_log_prefix = "%Us(%u): "
 
# Max. number of lines a mail process is allowed to log per second before it's
# throttled. 0 means unlimited. Typically there's no need to change this
# unless you're using mail_log plugin, which may log a lot. This setting is
# ignored while mail_debug=yes to avoid pointless throttling.
#mail_log_max_lines_per_sec = 10
 
# Don't use mmap() at all. This is required if you store indexes to shared
# filesystems (NFS or clustered filesystem).
#mmap_disable = no
mmap_disable = yes
 
# Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL
# since version 3, so this should be safe to use nowadays by default.
#dotlock_use_excl = yes
 
# Don't use fsync() or fdatasync() calls. This makes the performance better
# at the cost of potential data loss if the server (or the file server)
# goes down.
#fsync_disable = no
 
# Mail storage exists in NFS. Set this to yes to make Dovecot flush NFS caches
# whenever needed. If you're using only a single mail server this isn't needed.
#mail_nfs_storage = no
mail_nfs_storage = yes
# Mail index files also exist in NFS. Setting this to yes requires
# mmap_disable=yes and fsync_disable=no.
#mail_nfs_index = no
mail_nfs_index = yes
 
# Locking method for index files. Alternatives are fcntl, flock and dotlock.
# Dotlocking uses some tricks which may create more disk I/O than other locking
# methods. NFS users: flock doesn't work, remember to change mmap_disable.
#lock_method = fcntl
 
# Drop all privileges before exec()ing the mail process. This is mostly
# meant for debugging, otherwise you don't get core dumps. It could be a small
# security risk if you use single UID for multiple users, as the users could
# ptrace() each others processes then.
#mail_drop_priv_before_exec = no
 
# Show more verbose process titles (in ps). Currently shows user name and
# IP address. Useful for seeing who are actually using the IMAP processes
# (eg. shared mailboxes or if same uid is used for multiple accounts).
#verbose_proctitle = no
 
# Valid UID range for users, defaults to 500 and above. This is mostly
# to make sure that users can't log in as daemons or other system users.
# Note that denying root logins is hardcoded to dovecot binary and can't
# be done even if first_valid_uid is set to 0.
#first_valid_uid = 500
#last_valid_uid = 0
 
# Valid GID range for users, defaults to non-root/wheel. Users having
# non-valid GID as primary group ID aren't allowed to log in. If user
# belongs to supplementary groups with non-valid GIDs, those groups are
# not set.
#first_valid_gid = 1
#last_valid_gid = 0
 
# Maximum number of running mail processes. When this limit is reached,
# new users aren't allowed to log in.
#max_mail_processes = 512
 
# Set max. process size in megabytes. Most of the memory goes to mmap()ing
# files, so it shouldn't harm much even if this limit is set pretty high.
#mail_process_size = 256
mail_process_size = 0
 
# Maximum allowed length for mail keyword name. It's only forced when trying
# to create new keywords.
#mail_max_keyword_length = 50
 
# ':' separated list of directories under which chrooting is allowed for mail
# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too).
# This setting doesn't affect login_chroot, mail_chroot or auth chroot
# settings. If this setting is empty, "/./" in home dirs are ignored.
# WARNING: Never add directories here which local users can modify, that
# may lead to root exploit. Usually this should be done only if you don't
# allow shell access for users. <doc/wiki/Chrooting.txt>
#valid_chroot_dirs = 
 
# Default chroot directory for mail processes. This can be overridden for
# specific users in user database by giving /./ in user's home directory
# (eg. /home/./user chroots into /home). Note that usually there is no real
# need to do chrooting, Dovecot doesn't allow users to access files outside
# their mail directory anyway. If your home directories are prefixed with
# the chroot directory, append "/." to mail_chroot. <doc/wiki/Chrooting.txt>
#mail_chroot = 
 
##
## Mailbox handling optimizations
##
 
# The minimum number of mails in a mailbox before updates are done to cache
# file. This allows optimizing Dovecot's behavior to do less disk writes at
# the cost of more disk reads.
#mail_cache_min_mail_count = 0
 
# When IDLE command is running, mailbox is checked once in a while to see if
# there are any new mails or other changes. This setting defines the minimum
# time in seconds to wait between those checks. Dovecot can also use dnotify,
# inotify and kqueue to find out immediately when changes occur.
#mailbox_idle_check_interval = 30
 
# Save mails with CR+LF instead of plain LF. This makes sending those mails
# take less CPU, especially with sendfile() syscall with Linux and FreeBSD.
# But it also creates a bit more disk I/O which may just make it slower.
# Also note that if other software reads the mboxes/maildirs, they may handle
# the extra CRs wrong and cause problems.
#mail_save_crlf = no
 
##
## Maildir-specific settings
##
 
# By default LIST command returns all entries in maildir beginning with a dot.
# Enabling this option makes Dovecot return only entries which are directories.
# This is done by stat()ing each entry, so it causes more disk I/O.
# (For systems setting struct dirent->d_type, this check is free and it's
# done always regardless of this setting)
#maildir_stat_dirs = no
 
# When copying a message, do it with hard links whenever possible. This makes
# the performance much better, and it's unlikely to have any side effects.
#maildir_copy_with_hardlinks = yes
 
# When copying a message, try to preserve the base filename. Only if the
# destination mailbox already contains the same name (ie. the mail is being
# copied there twice), a new name is given. The destination filename check is
# done only by looking at dovecot-uidlist file, so if something outside
# Dovecot does similar filename preserving copies, you may run into problems.
# NOTE: This setting requires maildir_copy_with_hardlinks = yes to work.
#maildir_copy_preserve_filename = no
 
##
## mbox-specific settings
##
 
# Which locking methods to use for locking mbox. There are four available:
#  dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe
#           solution. If you want to use /var/mail/ like directory, the users
#           will need write access to that directory.
#  dotlock_try: Same as dotlock, but if it fails because of permissions or
#               because there isn't enough disk space, just skip it.
#  fcntl  : Use this if possible. Works with NFS too if lockd is used.
#  flock  : May not exist in all systems. Doesn't work with NFS.
#  lockf  : May not exist in all systems. Doesn't work with NFS.
#
# You can use multiple locking methods; if you do the order they're declared
# in is important to avoid deadlocks if other MTAs/MUAs are using multiple
# locking methods as well. Some operating systems don't allow using some of
# them simultaneously.
#mbox_read_locks = fcntl
#mbox_write_locks = fcntl
 
# Maximum time in seconds to wait for lock (all of them) before aborting.
#mbox_lock_timeout = 300
 
# If dotlock exists but the mailbox isn't modified in any way, override the
# lock file after this many seconds.
#mbox_dotlock_change_timeout = 120
 
# When mbox changes unexpectedly we have to fully read it to find out what
# changed. If the mbox is large this can take a long time. Since the change
# is usually just a newly appended mail, it'd be faster to simply read the
# new mails. If this setting is enabled, Dovecot does this but still safely
# fallbacks to re-reading the whole mbox file whenever something in mbox isn't
# how it's expected to be. The only real downside to this setting is that if
# some other MUA changes message flags, Dovecot doesn't notice it immediately.
# Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK 
# commands.
#mbox_dirty_syncs = yes
 
# Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE,
# EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored.
#mbox_very_dirty_syncs = no
 
# Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK
# commands and when closing the mailbox). This is especially useful for POP3
# where clients often delete all mails. The downside is that our changes
# aren't immediately visible to other MUAs.
#mbox_lazy_writes = yes
 
# If mbox size is smaller than this (in kilobytes), don't write index files.
# If an index file already exists it's still read, just not updated.
#mbox_min_index_size = 0
 
##
## dbox-specific settings
##
 
# Maximum dbox file size in kilobytes until it's rotated.
#dbox_rotate_size = 2048
 
# Minimum dbox file size in kilobytes before it's rotated
# (overrides dbox_rotate_days)
#dbox_rotate_min_size = 16
 
# Maximum dbox file age in days until it's rotated. Day always begins from
# midnight, so 1 = today, 2 = yesterday, etc. 0 = check disabled.
#dbox_rotate_days = 0
 
##
## IMAP specific settings
##
 
protocol imap {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/imap-login
 
  # IMAP executable location. Changing this allows you to execute other
  # binaries before the imap process is executed.
  #
  # This would write rawlogs into ~/dovecot.rawlog/ directory:
  #   mail_executable = /usr/libexec/dovecot/rawlog /usr/libexec/dovecot/imap
  #
  # This would attach gdb into the imap process and write backtraces into
  # /tmp/gdbhelper.* files:
  #   mail_executable = /usr/libexec/dovecot/gdbhelper /usr/libexec/dovecot/imap
  #
  #mail_executable = /usr/libexec/dovecot/imap
 
  # Maximum IMAP command line length in bytes. Some clients generate very long
  # command lines with huge mailboxes, so you may need to raise this if you get
  # "Too long argument" or "IMAP command line too large" errors often.
  #imap_max_line_length = 65536
 
  # Maximum number of IMAP connections allowed for a user from each IP address.
  # NOTE: The username is compared case-sensitively.
  #mail_max_userip_connections = 10
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/imap
 
  # IMAP logout format string:
  #  %i - total number of bytes read from client
  #  %o - total number of bytes sent to client
  #imap_logout_format = bytes=%i/%o
 
  # Override the IMAP CAPABILITY response.
  #imap_capability = 
 
  # ID field names and values to send to clients. Using * as the value makes
  # Dovecot use the default value. The following fields have default values
  # currently: name, version, os, os-version, support-url, support-email.
  #imap_id_send = 
 
  # ID fields sent by client to log. * means everything.
  #imap_id_log =
 
  # Workarounds for various client bugs:
  #   delay-newmail:
  #     Send EXISTS/RECENT new mail notifications only when replying to NOOP
  #     and CHECK commands. Some clients ignore them otherwise, for example OSX
  #     Mail (<v2.1). Outlook Express breaks more badly though, without this it
  #     may show user "Message no longer in server" errors. Note that OE6 still
  #     breaks even with this workaround if synchronization is set to
  #     "Headers Only".
  #   netscape-eoh:
  #     Netscape 4.x breaks if message headers don't end with the empty "end of
  #     headers" line. Normally all messages have this, but setting this
  #     workaround makes sure that Netscape never breaks by adding the line if
  #     it doesn't exist. This is done only for FETCH BODY[HEADER.FIELDS..]
  #     commands. Note that RFC says this shouldn't be done.
  #   tb-extra-mailbox-sep:
  #     With mbox storage a mailbox can contain either mails or submailboxes,
  #     but not both. Thunderbird separates these two by forcing server to
  #     accept '/' suffix in mailbox names in subscriptions list.
  # The list is space-separated.
  #imap_client_workarounds = 
  imap_client_workarounds = delay-newmail outlook-idle netscape-eoh tb-extra-mailbox-sep
}
 
##
## POP3 specific settings
##
 
protocol pop3 {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/pop3-login
 
  # POP3 executable location. See IMAP's mail_executable above for examples
  # how this could be changed.
  #mail_executable = /usr/libexec/dovecot/pop3
 
  # Don't try to set mails non-recent or seen with POP3 sessions. This is
  # mostly intended to reduce disk I/O. With maildir it doesn't move files
  # from new/ to cur/, with mbox it doesn't write Status-header.
  #pop3_no_flag_updates = no
 
  # Support LAST command which exists in old POP3 specs, but has been removed
  # from new ones. Some clients still wish to use this though. Enabling this
  # makes RSET command clear all \Seen flags from messages.
  #pop3_enable_last = no
 
  # If mail has X-UIDL header, use it as the mail's UIDL.
  #pop3_reuse_xuidl = no
 
  # Keep the mailbox locked for the entire POP3 session.
  #pop3_lock_session = no
 
  # POP3 UIDL (unique mail identifier) format to use. You can use following
  # variables, along with the variable modifiers described in
  # doc/wiki/Variables.txt (e.g. %Uf for the filename in uppercase)
  #
  #  %v - Mailbox's IMAP UIDVALIDITY
  #  %u - Mail's IMAP UID
  #  %m - MD5 sum of the mailbox headers in hex (mbox only)
  #  %f - filename (maildir only)
  #
  # If you want UIDL compatibility with other POP3 servers, use:
  #  UW's ipop3d         : %08Xv%08Xu
  #  Courier             : %f or %v-%u (both might be used simultaneosly)
  #  Cyrus (<= 2.1.3)    : %u
  #  Cyrus (>= 2.1.4)    : %v.%u
  #  Dovecot v0.99.x     : %v.%u
  #  tpop3d              : %Mf
  #
  # Note that Outlook 2003 seems to have problems with %v.%u format which was
  # Dovecot's default, so if you're building a new server it would be a good
  # idea to change this. %08Xu%08Xv should be pretty fail-safe.
  #
  #pop3_uidl_format = %08Xu%08Xv
 
  # POP3 logout format string:
  #  %i - total number of bytes read from client
  #  %o - total number of bytes sent to client
  #  %t - number of TOP commands
  #  %p - number of bytes sent to client as a result of TOP command
  #  %r - number of RETR commands
  #  %b - number of bytes sent to client as a result of RETR command
  #  %d - number of deleted messages
  #  %m - number of messages (before deletion)
  #  %s - mailbox size in bytes (before deletion)
  #pop3_logout_format = top=%t/%p, retr=%r/%b, del=%d/%m, size=%s
 
  # Maximum number of POP3 connections allowed for a user from each IP address.
  # NOTE: The username is compared case-sensitively.
  #mail_max_userip_connections = 3
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/pop3
 
  # Workarounds for various client bugs:
  #   outlook-no-nuls:
  #     Outlook and Outlook Express hang if mails contain NUL characters.
  #     This setting replaces them with 0x80 character.
  #   oe-ns-eoh:
  #     Outlook Express and Netscape Mail breaks if end of headers-line is
  #     missing. This option simply sends it if it's missing.
  # The list is space-separated.
  #pop3_client_workarounds = 
  pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
}
 
##
## MANAGESIEVE specific settings
##
 
protocol managesieve {
  # Login executable location.
  #login_executable = /usr/libexec/dovecot/managesieve-login
 
  # MANAGESIEVE executable location. See IMAP's mail_executable above for 
  # examples how this could be changed.
  #mail_executable = /usr/libexec/dovecot/managesieve
 
  # Maximum MANAGESIEVE command line length in bytes. This setting is 
  # directly borrowed from IMAP. But, since long command lines are very
  # unlikely with MANAGESIEVE, changing this will not be very useful.  
  #managesieve_max_line_length = 65536
 
  # If, for some inobvious reason, the sieve_storage remains unset, the 
  # managesieve daemon uses the specification of the mail_location to find out 
  # where to store the sieve files (see explaination in README.managesieve). 
  # The example below, when uncommented, overrides any global mail_location 
  # specification and stores all the scripts in '~/mail/sieve' if sieve_storage 
  # is unset. However, you should always use the sieve_storage setting.
  # mail_location = mbox:~/mail
 
  # To fool managesieve clients that are focused on timesieved you can
  # specify the IMPLEMENTATION capability that the dovecot reports to clients 
  # (default: dovecot).
  #managesieve_implementation_string = Cyrus timsieved v2.2.13
}
 
##
## LDA specific settings
##
 
protocol lda {
  # Address to use when sending rejection mails.
  postmaster_address = postmaster@example.com
 
  # Hostname to use in various parts of sent mails, eg. in Message-Id.
  # Default is the system's real hostname.
  #hostname = 
 
  # Support for dynamically loadable plugins. mail_plugins is a space separated
  # list of plugins to load.
  #mail_plugins = 
  #mail_plugin_dir = /usr/lib/dovecot/lda
 
  # If user is over quota, return with temporary failure instead of
  # bouncing the mail.
  #quota_full_tempfail = no
 
  # Format to use for logging mail deliveries. You can use variables:
  #  %$ - Delivery status message (e.g. "saved to INBOX")
  #  %m - Message-ID
  #  %s - Subject
  #  %f - From address
  #deliver_log_format = msgid=%m: %$
 
  # Binary to use for sending mails.
  #sendmail_path = /usr/lib/sendmail
 
  # Subject: header to use for rejection mails. You can use the same variables
  # as for rejection_reason below.
  #rejection_subject = Rejected: %s
 
  # Human readable error message for rejection mails. You can use variables:
  #  %n = CRLF, %r = reason, %s = original subject, %t = recipient
  #rejection_reason = Your message to <%t> was automatically rejected:%n%r
 
  # UNIX socket path to master authentication server to find users.
  #auth_socket_path = /var/run/dovecot/auth-master
}
 
##
## Authentication processes
##
 
# Executable location
#auth_executable = /usr/libexec/dovecot/dovecot-auth
 
# Set max. process size in megabytes.
#auth_process_size = 256
 
# Authentication cache size in kilobytes. 0 means it's disabled.
# Note that bsdauth, PAM and vpopmail require cache_key to be set for caching
# to be used.
#auth_cache_size = 0
# Time to live in seconds for cached data. After this many seconds the cached
# record is no longer used, *except* if the main database lookup returns
# internal failure. We also try to handle password changes automatically: If
# user's previous authentication was successful, but this one wasn't, the
# cache isn't used. For now this works only with plaintext authentication.
#auth_cache_ttl = 3600
# TTL for negative hits (user not found). 0 disables caching them completely.
#auth_cache_negative_ttl = 3600
 
# Space separated list of realms for SASL authentication mechanisms that need
# them. You can leave it empty if you don't want to support multiple realms.
# Many clients simply use the first one listed here, so keep the default realm
# first.
#auth_realms =
 
# Default realm/domain to use if none was specified. This is used for both
# SASL realms and appending @domain to username in plaintext logins.
#auth_default_realm = 
 
# List of allowed characters in username. If the user-given username contains
# a character not listed in here, the login automatically fails. This is just
# an extra check to make sure user can't exploit any potential quote escaping
# vulnerabilities with SQL/LDAP databases. If you want to allow all characters,
# set this value to empty.
#auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@
 
# Username character translations before it's looked up from databases. The
# value contains series of from -> to characters. For example "#@/@" means
# that '#' and '/' characters are translated to '@'.
#auth_username_translation =
 
# Username formatting before it's looked up from databases. You can use
# the standard variables here, eg. %Lu would lowercase the username, %n would
# drop away the domain if it was given, or "%n-AT-%d" would change the '@' into
# "-AT-". This translation is done after auth_username_translation changes.
#auth_username_format =
 
# If you want to allow master users to log in by specifying the master
# username within the normal username string (ie. not using SASL mechanism's
# support for it), you can specify the separator character here. The format
# is then <username><separator><master username>. UW-IMAP uses "*" as the
# separator, so that could be a good choice.
#auth_master_user_separator =
 
# Username to use for users logging in with ANONYMOUS SASL mechanism
#auth_anonymous_username = anonymous
 
# More verbose logging. Useful for figuring out why authentication isn't
# working.
#auth_verbose = no
 
# Even more verbose logging for debugging purposes. Shows for example SQL
# queries.
#auth_debug = no
 
# In case of password mismatches, log the passwords and used scheme so the
# problem can be debugged. Enabling this also enables auth_debug.
#auth_debug_passwords = no
 
# Maximum number of dovecot-auth worker processes. They're used to execute
# blocking passdb and userdb queries (eg. MySQL and PAM). They're
# automatically created and destroyed as needed.
#auth_worker_max_count = 30
 
# Host name to use in GSSAPI principal names. The default is to use the
# name returned by gethostname(). Use "$ALL" to allow all keytab entries.
#auth_gssapi_hostname =
 
# Kerberos keytab to use for the GSSAPI mechanism. Will use the system 
# default (usually /etc/krb5.keytab) if not specified.
#auth_krb5_keytab = 
 
# Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon and
# ntlm_auth helper. <doc/wiki/Authentication/Mechanisms/Winbind.txt>
#auth_use_winbind = no
 
# Path for Samba's ntlm_auth helper binary.
#auth_winbind_helper_path = /usr/bin/ntlm_auth
 
# Number of seconds to delay before replying to failed authentications.
#auth_failure_delay = 2
 
auth default {
  # Space separated list of wanted authentication mechanisms:
  #   plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi otp skey
  #   gss-spnego
  # NOTE: See also disable_plaintext_auth setting.
  mechanisms = plain
 
  #
  # Password database is used to verify user's password (and nothing more).
  # You can have multiple passdbs and userdbs. This is useful if you want to
  # allow both system users (/etc/passwd) and virtual users to login without
  # duplicating the system users into virtual database.
  #
  # <doc/wiki/PasswordDatabase.txt>
  #
  # By adding master=yes setting inside a passdb you make the passdb a list
  # of "master users", who can log in as anyone else. Unless you're using PAM,
  # you probably still want the destination user to be looked up from passdb
  # that it really exists. This can be done by adding pass=yes setting to the
  # master passdb. <doc/wiki/Authentication.MasterUsers.txt>
 
  # Users can be temporarily disabled by adding a passdb with deny=yes.
  # If the user is found from that database, authentication will fail.
  # The deny passdb should always be specified before others, so it gets
  # checked first. Here's an example:
 
  #passdb passwd-file {
    # File contains a list of usernames, one per line
    #args = /etc/dovecot.deny
    #deny = yes
  #}
 
  # PAM authentication. Preferred nowadays by most systems. 
  # Note that PAM can only be used to verify if user's password is correct,
  # so it can't be used as userdb. If you don't want to use a separate user
  # database (passwd usually), you can use static userdb.
  # REMEMBER: You'll need /etc/pam.d/dovecot file created for PAM
  # authentication to actually work. <doc/wiki/PasswordDatabase.PAM.txt>
  passdb pam {
    # [session=yes] [setcred=yes] [failure_show_msg=yes] [max_requests=<n>]
    # [cache_key=<key>] [<service name>]
    #
    # session=yes makes Dovecot open and immediately close PAM session. Some
    # PAM plugins need this to work, such as pam_mkhomedir.
    #
    # setcred=yes makes Dovecot establish PAM credentials if some PAM plugins
    # need that. They aren't ever deleted though, so this isn't enabled by
    # default.
    #
    # max_requests specifies how many PAM lookups to do in one process before
    # recreating the process. The default is 100, because many PAM plugins
    # leak memory.
    #
    # cache_key can be used to enable authentication caching for PAM
    # (auth_cache_size also needs to be set). It isn't enabled by default
    # because PAM modules can do all kinds of checks besides checking password,
    # such as checking IP address. Dovecot can't know about these checks
    # without some help. cache_key is simply a list of variables (see
    # doc/wiki/Variables.txt) which must match for the cached data to be used.
    # Here are some examples:
    #   %u - Username must match. Probably sufficient for most uses.
    #   %u%r - Username and remote IP address must match.
    #   %u%s - Username and service (ie. IMAP, POP3) must match.
    # 
    # The service name can contain variables, for example %Ls expands to
    # pop3 or imap.
    #
    # Some examples:
    #   args = session=yes %Ls
    #   args = cache_key=%u dovecot
    #args = dovecot
  }
 
  # System users (NSS, /etc/passwd, or similiar)
  # In many systems nowadays this uses Name Service Switch, which is
  # configured in /etc/nsswitch.conf. <doc/wiki/AuthDatabase.Passwd.txt>
  #passdb passwd {
    # [blocking=yes] - See userdb passwd for explanation
    #args = 
  #}
 
  # Shadow passwords for system users (NSS, /etc/shadow or similiar).
  # Deprecated by PAM nowadays.
  # <doc/wiki/PasswordDatabase.Shadow.txt>
  #passdb shadow {
    # [blocking=yes] - See userdb passwd for explanation
    #args = 
  #}
 
  # PAM-like authentication for OpenBSD.
  # <doc/wiki/PasswordDatabase.BSDAuth.txt>
  #passdb bsdauth {
    # [cache_key=<key>] - See cache_key in PAM for explanation.
    #args =
  #}
 
  # passwd-like file with specified location
  # <doc/wiki/AuthDatabase.PasswdFile.txt>
  #passdb passwd-file {
    # [scheme=<default password scheme>] [username_format=<format>]
    # <Path for passwd-file>
    #args = 
  #}
 
  # checkpassword executable authentication
  # NOTE: You will probably want to use "userdb prefetch" with this.
  # <doc/wiki/AuthDatabase.CheckPassword.txt>
  #passdb checkpassword {
    # Path for checkpassword binary
    #args = 
  #}
 
  # SQL database <doc/wiki/AuthDatabase.SQL.txt>
  #passdb sql {
    # Path for SQL configuration file, see doc/dovecot-sql-example.conf
    #args = 
  #}
 
  # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
  #passdb ldap {
    # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
    #args = 
  #}
 
  # vpopmail authentication <doc/wiki/AuthDatabase.VPopMail.txt>
  #passdb vpopmail {
    # [cache_key=<key>] - See cache_key in PAM for explanation.
    # [quota_template=<template>] - %q expands to Maildir++ quota
    #   (eg. quota_template=quota_rule=*:backend=%q)
    #args =
  #}
 
  #
  # User database specifies where mails are located and what user/group IDs
  # own them. For single-UID configuration use "static".
  #
  # <doc/wiki/UserDatabase.txt>
  #
 
  # "prefetch" user database means that the passdb already provided the
  # needed information and there's no need to do a separate userdb lookup.
  # This can be made to work with SQL and LDAP databases, see their example
  # configuration files for more information how to do it.
  # <doc/wiki/UserDatabase.Prefetch.txt>
  #userdb prefetch {
  #}
 
  # System users (NSS, /etc/passwd, or similiar). In many systems nowadays this
  # uses Name Service Switch, which is configured in /etc/nsswitch.conf.
  # <doc/wiki/AuthDatabase.Passwd.txt>
  userdb passwd {
    # [blocking=yes] - By default the lookups are done in the main dovecot-auth
    # process. This setting causes the lookups to be done in auth worker
    # proceses. Useful with remote NSS lookups that may block.
    # NOTE: Be sure to use this setting with nss_ldap or users might get
    # logged in as each others!
    #args = 
  }
 
  # passwd-like file with specified location
  # <doc/wiki/AuthDatabase.PasswdFile.txt>
  #userdb passwd-file {
    # [username_format=<format>] <Path for passwd-file>
    #args =
  #}
 
  # checkpassword executable user database lookup
  # <doc/wiki/AuthDatabase.CheckPassword.txt>
  #userdb checkpassword {
    # Path for checkpassword binary
    #args = 
  #}
 
  # static settings generated from template <doc/wiki/UserDatabase.Static.txt>
  #userdb static {
    # Template for the fields. Can return anything a userdb could normally
    # return. For example:
    #
    #  args = uid=500 gid=500 home=/var/mail/%u
    #
    # If you use deliver, it needs to look up users only from the userdb. This
    # of course doesn't work with static because there is no list of users.
    # Normally static userdb handles this by doing a passdb lookup. This works
    # with most passdbs, with PAM being the most notable exception. If you do
    # the user verification another way, you can add allow_all_users=yes to
    # the args in which case the passdb lookup is skipped.
    #
    #args =
  #}
 
  # SQL database <doc/wiki/AuthDatabase.SQL.txt>
  #userdb sql {
    # Path for SQL configuration file, see doc/dovecot-sql-example.conf
    #args = 
  #}
 
  # LDAP database <doc/wiki/AuthDatabase.LDAP.txt>
  #userdb ldap {
    # Path for LDAP configuration file, see doc/dovecot-ldap-example.conf
    #args = 
  #}
 
  # vpopmail <doc/wiki/AuthDatabase.VPopMail.txt>
  #userdb vpopmail {
  #}
 
  # User to use for the process. This user needs access to only user and
  # password databases, nothing else. Only shadow and pam authentication
  # requires roots, so use something else if possible. Note that passwd
  # authentication with BSDs internally accesses shadow files, which also
  # requires roots. Note that this user is NOT used to access mails.
  # That user is specified by userdb above.
  user = root
 
  # Directory where to chroot the process. Most authentication backends don't
  # work if this is set, and there's no point chrooting if auth_user is root.
  # Note that valid_chroot_dirs isn't needed to use this setting.
  #chroot = 
 
  # Number of authentication processes to create
  #count = 1
 
  # Require a valid SSL client certificate or the authentication fails.
  #ssl_require_client_cert = no
 
  # Take the username from client's SSL certificate, using 
  # X509_NAME_get_text_by_NID() which returns the subject's DN's
  # CommonName. 
  #ssl_username_from_cert = no
 
  # It's possible to export the authentication interface to other programs:
  #socket listen {
    #master {
      # Master socket provides access to userdb information. It's typically
      # used to give Dovecot's local delivery agent access to userdb so it
      # can find mailbox locations.
      #path = /var/run/dovecot/auth-master
      #mode = 0600
      # Default user/group is the one who started dovecot-auth (root)
      #user = 
      #group = 
    #}
    #client {
      # The client socket is generally safe to export to everyone. Typical use
      # is to export it to your SMTP server so it can do SMTP AUTH lookups
      # using it.
      #path = /var/run/dovecot/auth-client
      #mode = 0660
    #}
  #}
}
 
# If you wish to use another authentication server than dovecot-auth, you can
# use connect sockets. They are assumed to be already running, Dovecot's master
# process only tries to connect to them. They don't need any other settings
# than the path for the master socket, as the configuration is done elsewhere.
# Note that the client sockets must exist in the login_dir.
#auth external {
#  socket connect {
#    master {
#      path = /var/run/dovecot/auth-master
#    }
#  }
#}
 
##
## Dictionary server settings
##
 
# Dictionary can be used by some plugins to store key=value lists.
# Currently this is only used by dict quota backend. The dictionary can be
# used either directly or though a dictionary server. The following dict block
# maps dictionary names to URIs when the server is used. These can then be
# referenced using URIs in format "proxy::<name>".
 
dict {
  #quota = mysql:/etc/dovecot-dict-quota.conf 
  #expire = db:/var/lib/dovecot/expire.db
}
 
# Path to Berkeley DB's configuration file. See doc/dovecot-db-example.conf
#dict_db_config = 
 
##
## Plugin settings
##
 
plugin {
  # Here you can give some extra environment variables to mail processes.
  # This is mostly meant for passing parameters to plugins. %variable
  # expansion is done for all values.
 
  # Quota plugin. Multiple backends are supported:
  #   dirsize: Find and sum all the files found from mail directory.
  #            Extremely SLOW with Maildir. It'll eat your CPU and disk I/O.
  #   dict: Keep quota stored in dictionary (eg. SQL)
  #   maildir: Maildir++ quota
  #   fs: Read-only support for filesystem quota
  #
  # Quota limits are set using "quota_rule" parameters, either in here or in
  # userdb. It's also possible to give mailbox-specific limits, for example:
  #   quota_rule = *:storage=1048576
  #   quota_rule2 = Trash:storage=102400
  # User has now 1GB quota, but when saving to Trash mailbox the user gets
  # additional 100MB.
  #
  # Multiple quota roots are also possible, for example:
  #   quota = dict:user::proxy::quota
  #   quota2 = dict:domain:%d:proxy::quota_domain
  #   quota_rule = *:storage=102400
  #   quota2_rule = *:storage=1048576
  # Gives each user their own 100MB quota and one shared 1GB quota within
  # the domain.
  #
  # You can execute a given command when user exceeds a specified quota limit.
  # Each quota root has separate limits. Only the command for the first
  # exceeded limit is excecuted, so put the highest limit first.
  # Note that % needs to be escaped as %%, otherwise "% " expands to empty.
  #   quota_warning = storage=95%% /usr/local/bin/quota-warning.sh 95
  #   quota_warning2 = storage=80%% /usr/local/bin/quota-warning.sh 80
  #quota = maildir
 
  # ACL plugin. vfile backend reads ACLs from "dovecot-acl" file from maildir
  # directory. You can also optionally give a global ACL directory path where
  # ACLs are applied to all users' mailboxes. The global ACL directory contains
  # one file for each mailbox, eg. INBOX or sub.mailbox. cache_secs parameter
  # specifies how many seconds to wait between stat()ing dovecot-acl file
  # to see if it changed.
  #acl = vfile:/etc/dovecot-acls:cache_secs=300
 
  # To let users LIST mailboxes shared by other users, Dovecot needs a
  # shared mailbox dictionary. For example:
  #acl_shared_dict = file:/var/lib/dovecot/shared-mailboxes
 
  # Convert plugin. If set, specifies the source storage path which is
  # converted to destination storage (mail_location) when the user logs in.
  # The existing mail directory is renamed to <dir>-converted.
  #convert_mail = mbox:%h/mail
  # Skip mailboxes which we can't open successfully instead of aborting.
  #convert_skip_broken_mailboxes = no
  # Skip directories beginning with '.'
  #convert_skip_dotdirs = no
  # If source storage has mailbox names with destination storage's hierarchy
  # separators, replace them with this character.
  #convert_alt_hierarchy_char = _
 
  # Trash plugin. When saving a message would make user go over quota, this
  # plugin automatically deletes the oldest mails from configured mailboxes
  # until the message can be saved within quota limits. The configuration file
  # is a text file where each line is in format: <priority> <mailbox name>
  # Mails are first deleted in lowest -> highest priority number order
  #trash = /etc/dovecot-trash.conf
 
  # Expire plugin. Mails are expunged from mailboxes after being there the
  # configurable time. The first expiration date for each mailbox is stored in
  # a dictionary so it can be quickly determined which mailboxes contain
  # expired mails. The actual expunging is done in a nightly cronjob, which
  # you must set up:
  #   dovecot --exec-mail ext /usr/libexec/dovecot/expire-tool
  #expire = Trash 7 Spam 30
  #expire_dict = proxy::expire
 
  # Lazy expunge plugin. Currently works only with maildirs. When a user
  # expunges mails, the mails are moved to a mailbox in another namespace
  # (1st). When a mailbox is deleted, the mailbox is moved to another namespace
  # (2nd) as well. Also if the deleted mailbox had any expunged messages,
  # they're moved to a 3rd namespace. The mails won't be counted in quota,
  # and they're not deleted automatically (use a cronjob or something).
  #lazy_expunge = .EXPUNGED/ .DELETED/ .DELETED/.EXPUNGED/
 
  # Events to log. Also available: flag_change append
  #mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename
  # Group events within a transaction to one line.
  #mail_log_group_events = 
  # Available fields: uid, box, msgid, from, subject, size, vsize, flags
  # size and vsize are available only for expunge and copy events.
  #mail_log_fields = uid box msgid size
 
  # Sieve plugin (http://wiki.dovecot.org/LDA/Sieve) and ManageSieve service
  # 
  # Location of the active script. When ManageSieve is used this is actually 
  # a symlink pointing to the active script in the sieve storage directory. 
  #sieve=~/.dovecot.sieve
  #
  # The path to the directory where the personal Sieve scripts are stored. For 
  # ManageSieve this is where the uploaded scripts are stored.
  #sieve_dir=~/sieve
}

Optional Extras

Setting up SPF

Method 1: use the C based SPF milter, “smf-spf”

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yum install smf-spf

Add the following to sendmail.mc and re-make sendmail.cf

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dnl **
dnl ** enable smf-spf (Sender Policy Framework) **
dnl **
define(`confMILTER_MACROS_HELO', confMILTER_MACROS_HELO`, {verify}')dnl
INPUT_MAIL_FILTER(`smf-spf', `S=unix:/var/run/smfs/smf-spf.sock, T=S:30s;R:1m')dnl

Starting it up

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/etc/init.d/smf-spf restart
/etc/init.d/sendmail restart

Don’t forget to run chkconfig if you want to make smf-spf start up permanentally between reboots.

9 comments to How to Setup a Mail Server on CentOS 5

  • Thanks for the guide, do you happen to have any information on getting ClamAV working with Postfix? I’m currently working on setting up ClamAV-milter with Postfix/Dovecot/Spamassassin (all with MySQL config) and I guess the above should all work for me with modificates to Postfix’s master.cf file. I followed another guide but things seemed to not work. Any advice you could give would be appreciated. Many thanks.

  • Plastix

    so after installing all these… how can i test if its working??

    sorry for the questions but i am really new to centOS. i have an assignment.. to set up a mail server..

    help..

    • Take a look at this page on Debugging Sendmail Problems

      Additionally take a look at this URL. There are a couple of basics tests that you can run. The first is to use the telnet command. This will check that the sendmail server is running and accepting mail. You can check the /var/log/maillog and see that the emails are getting accepted and delivered correctly.

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      % telnet localhost 25
      HELO example.com
      MAIL From: TheBoss@example.com
      RCPT To: sysadmin@example.com                     <-- Change this to your own email to see results.
      DATA
      Subject: Think we're insecure...
      I have a feeling our mail server is being abused...
      .
      QUIT

      The other approach is to call sendmail directly in a verbose mode constructing various test emails like this:

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      % echo "Subject: test" | /usr/lib/sendmail -v me@domain.com
      me@domain.com... Connecting to [127.0.0.1] via relay...
      220 localhost.localdomain ESMTP Sendmail 8.14.4/8.14.4; Sun, 15 May 2011 02:14:18 -0400
      >>> EHLO localhost.localdomain
      250-localhost.localdomain Hello grinchy [127.0.0.1], pleased to meet you
      250-ENHANCEDSTATUSCODES
      250-PIPELINING
      250-8BITMIME
      250-SIZE
      250-DSN
      250-ETRN
      250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5
      250-DELIVERBY
      250 HELP
      >>> MAIL From: SIZE=14 AUTH=saml@localhost.localdomain
      250 2.1.0 ... Sender ok
      >>> RCPT To:
      >>> DATA
      250 2.1.5 ... Recipient ok
      354 Enter mail, end with "." on a line by itself
      >>> .
      250 2.0.0 p4F6EI5t010281 Message accepted for delivery
      me@domain.com... Sent (p4F6EI5t010281 Message accepted for delivery)
      Closing connection to [127.0.0.1]
      >>> QUIT
      221 2.0.0 localhost.localdomain closing connection

      The final way to test your sendmail configuration is by again calling sendmail via the command line but this time we’ll be using it’s “address test” mode. This can be done by giving it the -bt switches. For example:

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      % sendmail -bt
      > 3,0 sam@domain.org
      canonify           input: sam @ domain . org
      Canonify2          input: sam 
      Canonify2        returns: sam 
      canonify         returns: sam 
      parse              input: sam 
      Parse0             input: sam 
      Parse0           returns: sam 
      ParseLocal         input: sam 
      ParseLocal       returns: sam 
      Parse1             input: sam 
      Parse1           returns: $# local $: sam
      parse            returns: $# local $: sam

      In this example you can see that email sent to sam@domain.org ultimately get’s delivered locally. Check out this URL for more information on sendmail’s “address test” mode.

  • Plastix

    oh i see.Thanks.. i’ll install all the necessary packages then i’ll configure them.. i have a virtual ubuntu server as well.. tried setting up the mail system but it didn’t work fully… i telnet it but it stop responding on the part of “MAIL FROM.” although cent OS is net entirely different, its really new to me because i am a windows user. then i started using ubuntu too.. for two years. i have dual boot. when i tried the centOS the locations and files for configurations are new to me. anyways…. i’ll do this tuturial…hoping for the best..its my assignment….

    Thanks a lot sir..

    • Yes even though Ubuntu and CentOS are both Linux there are inherent differences between the various distributions of Linux. In general, Fedora, CentOS, and RHEL (Red Hat Enterprise Linux) are all similar to each other since they share the same core code base. Ubuntu, Xbuntu, Kbuntu, Mint etc. are all derivatives from Debian, so they are all very similar with each other, and in fact share a lot of the same packages and directory structure. The other large distros are SUSE (openSUSE, SUSE Linux Enterprise Server, & SUSE Linux Enterprise Desktop), Slackware, ArchLinux, and Gentoo.

      BOTTOM LINE: They all use the Linux Kernel but their directory structures, package management, etc. can be significantly different!

  • Plastix

    just to provide clarity to you… i have dual boot.. windows and ubuntu… but i also have virtual ubuntu server and cent OS server… i was confusing you previously.. sorry..

    THanks again

  • Plastix

    __________________________________________________________________________________________________
    # install yum repo package
    rpm -Uvh http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-7.rhel5.noarch.rpm

    # import repo’s GPG Key
    rpm –import http://www.city-fan.org/ftp/contrib/yum-repo/CITY-FAN.ORG-GPG-KEY
    __________________________________________________________________________________________________

    I tried doing this but there was an error…

    Retrieving http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-7.rhel5.noarch.rpm
    error: skipping http://www.city-fan.org/ftp/contrib/yum-repo/city-fan.org-release-1-7.rhel5.noarch.rpm – transfer failed – Unknown or unexpected error
    …..

    • Looks like this has changed since the last time I installed it. I’ve updated the link in the article above, thanks for letting me know. In the future if someone tries to access the city-fan.org yum repo you can hit their main page and then browse to your particular distros’ RPM.

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