1. Install
the dovecot package on Sendmail server.
[root@mail01 mail]# yum install
dovecot*
[root@mail01 mail]# rpm -qa | grep dovecot
dovecot-2.0.9-5.el6.x86_64
dovecot-pigeonhole-2.0.9-5.el6.x86_64
2.
Open /etc/dovecot/dovecot.conf file and change
the following parameters.
[root@mail01
mail]# vi /etc/dovecot/dovecot.conf
protocols
= imap pop3 lmtp sieve
mail_location
= maildir:~/Maildir
#
disable_plaintext_auth value is no if
pop3 need to connect on 110 port
otherwise it will connect only on secure PLAIN connection 995 port.
Comment out if need to connect on 110 port.
#disable_plaintext_auth
= no
Sieve (Mail filtering Language) :
Sieve is a language for filtering
e-mail messages. It support as a plug-in for
Dovecot's Local Delivery Agent (LDA) and also for its LMTP service. The plug-in
implements a Sieve interpreter, which filters incoming messages using a script
specified in the Sieve language. The Sieve script is provided by the user
through New Webmail UI and, using that Sieve script, the user can
customize how incoming messages are handled. Messages can be delivered to
specific folders, forwarded, rejected, discarded, etc.
The managesieve daemon will listen on
port 2000 but some other version it listen on port 2000. request to kindly
change 20-managesieve.conf file
if it is not listen on port 2000
update /etc/dovecot/conf.d/20-managesieve.conf
service managesieve-login {
inet_listener sieve {
port = 2000
}
}
Sieve
Interpreter Configuration:
The part of the Sieve interpreter
configuration that is relevant for ManageSieve mainly consists of the settings
that specify where the user's scripts are stored and where the active script is
located. The ManageSieve service primarily uses the following Sieve interpreter
settings in the plugin section of the Dovecot
configuration(/etc/dovecot/conf.d) update /etc/dovecot/conf.d/90-sieve.conf
:
This specifies the path to the
directory where the uploaded scripts are stored. Scripts are stored as separate
files with extension '.sieve'.
sieve = ~/.dovecot.sieve
This specifies the location of the
symbolic link pointing to the active script in the Sieve storage directory. The
Sieve interpreter uses this setting to locate the main script file that needs
to be executed upon delivery.
Enabling Sieve plugin:
To use Sieve, you will first need
to make sure you are using Dovecot LDA or LMTP (this settings is already has been defined in above 'Protocol
Configuration' section)for delivering incoming mail to users' mailboxes.
Then, you need to enable the Pigeonhole Sieve plugin in your configuration:
update
/etc/dovecot/conf.d/15-lda.conf
protocol lda
{
mail_plugins
= $mail_plugins sieve
}
update /etc/dovecot/conf.d/20-lmtp.conf
protocol
lmtp {
mail_plugins
= $mail_plugins sieve
}
restart the dovecot
(/etc/init.d/dovecot restart) and check
#telnet centre-imap-server 2000
it should be listen
Dovecot LDA with MTA (Sendmail, Postfix
etc.):
The dovecot-lda is a local mail
delivery agent which takes mail from an MTA (sendmail, postfix etc.) and
delivers it to a user's mailbox, while keeping Dovecot index files up to date.
Main features of the dovecot-lda are:
1. Sieve
language support by the Pigeonhole sieve plugin
2. Mailbox
indexing during mail delivery, providing faster mailbox access later
3. Quota
enforcing by the quota plugin
To configure dovecot lda
with Sendmail kindly update below sendmail.cf file.
update the /etc/mail/sendmail.mc file by
making following entry.
dnl # FEATURE(local_procmail, `', `procmail -t -Y -a $h -d $u')dnl
FEATURE(`local_procmail',
`/usr/libexec/dovecot/dovecot-lda',`/usr/libexec/dovecot/dovecot-lda -d $u')
MODIFY_MAILER_FLAGS(`LOCAL', `-f')
MAILER(procmail)
Convert the sendmail.mc file sendmail.cf using m4 language.
And restart the sendmail daemon.
[root@mail01 certs]# cd /etc/mail
[root@mail01 mail]# m4 sendmail.mc >
sendmail.cf
[root@mail01 mail]# service sendmail restart
[root@mail01 mail]# chkconfig sendmail on
----------------------------------------------------------------------------------------------------------------------------
sendmail.cf (the mails will deliver through dovecot-lda instead of
procmail )
below 3
lines from sendmail.cf will be removed.
Mlocal, P=/usr/bin/procmail,
F=lsDFMAw5:/|@qSPfhn9, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL,
T=DNS/RFC822/X-Unix,
A=procmail -t -Y -a $h -d $u
and below 3
lines will be added into sendmail.cf automatically.
Mlocal,
P=/usr/libexec/dovecot/dovecot-lda, F=lsDFMAw5:/|@qSPhn9, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL,
T=DNS/RFC822/X-Unix,
A=/usr/libexec/dovecot/dovecot-lda
-d $u
---------------------------------------------------------------------------------------------------------------------------------
Quota:
First you
have the quota root backend configuration, this quota backend specifies the
method how Dovecot keeps track of the current quota usage. They don't (usually)
specify users' quota limits, that's done by returning extra fields from userdb.
To define
quota backend:
update /etc/dovecot/conf.d/90-quota.conf file
plugin {
quota = maildir:User quota
}
There are
different quota backends that Dovecot can use, but in this document we are
defining maildir backend here in this document we configure maildir backend:
·maildir: Store quota usage in Maildir++ maildirsize files. This is
the most commonly used quota for virtual users.
Enabling
quota plugins:
update /etc/dovecot/conf.d/10-mail.conf
mail_plugins
= $mail_plugins quota
update /etc/dovecot/conf.d/20-imap.conf
mail_plugins
= $mail_plugins imap_quota
It will reporting quota information via
IMAP.
To configure per user basis quota, we
need to maintain flat file (/etc/dovecot/users) in dovecot database
Note: After
creating user's home directory at your mail server you need to add user
information in /etc/dovecot/users file.
(the users
entries should be below like
username:x:uid:gid:Full
Name:HOME DIR:BASH:userdb_quota_rule=*:storage=2G
example
jitendrakumar:x:4321:4321:Jitendra
Kumar:/home/jitendrakumar:/bin/bash:userdb_quota_rule=*:storage=2G)
now define /etc/dovecot/users into configuration file
update /etc/dovecot/conf.d/auth-system.conf.ext
passdb {
driver
= pam
}
userdb {
driver
= passwd-file
args
= username_format=%u /etc/dovecot/users
}
Quota warnings:
Now configure Dovecot to run an
external command when user's quota exceeds a specified limit. Note that the
warning is ONLY executed at the exact time when the limit is being crossed.
update /opt/dovecot/etc/dovecot/conf.d/90-quota.conf
plugin {
quota_warning = storage=75%% quota-warning 75 %u
quota_warning2 = storage=90%% quota-warning 90 %u
}
service quota-warning {
executable = script /usr/local/bin/quota-warning.sh
unix_listener quota-warning {
mode = 0666
}
}
With the above example when user's
quota exceeds 75%, quota-warning.sh is executed with
parameter 75. The same goes for when quota exceeds 90%.
You have to create the quota-warning.sh
touch /usr/local/bin/quota-warning.sh
chmod 700
/usr/local/bin/quota-warning.sh
chmod +x /usr/local/bin/quota-warning.sh
Here is an example that sends a mail to
the user:
#!/bin/sh
PERCENT=$1
USER=$2
cat << EOF |
/usr/libexec/dovecot/deliver -d $USER -o "plugin/quota=maildir:User
quota"
From: mailadmin-centre@example.com
Subject: Mailbox Quota Warning:
$PERCENT% Full.
Mailbox quota report:
* Your mailbox is now $PERCENT% full, please clear some files for
further mails.
EOF
Over Quota:
If user is over quota, you can configure following settings in /etc/dovecot/conf.d/15-lda.conf
quota_full_tempfail
= yes (after
exceeding quota, mails will deliver to
queue directory instead of bounce back, after deleting mails from users or
increasing quota by mailadmin the mails will deliver to user INBOX automatically)
quota_full_tempfail
= no (after
exceeding quota mails will be bounce back)
