Dovecot

Dovecot is an IMAP and POP3 server.

The goal of this article is to setup dovecot, using PAM auth over SSL. It requires an SMTP server already working. You can follow the Sendmail guide to set up sendmail as your SMTP server.

Installation

Install the package dovecot and pam from the official repositories.

Create SSL certs

The dovecot package contains a script to create your SSL certificate and key. Before you run this script, create your settings file.

cp /etc/ssl/dovecot-openssl.cnf{.sample,}
vim /etc/ssl/dovecot-openssl.cnf

Then execute the script.

/usr/lib/dovecot/mkcert.sh

The cert/key pair is created under /etc/ssl/certs and /etc/ssl/private.

Configuration

• Create the /etc/pam.d/dovecot file, and put the following:

auth    required        pam_unix.so nullok
account required        pam_unix.so 

• Check the correct path where you mail is stored. Normally is /var/spool/mail.
• Edit the /etc/dovecot/dovecot.conf. Be sure you set the path of ssl_cert, ssl_key and mail_location correctly:

/etc/dovecot/dovecot.conf

listen = *
disable_plaintext_auth=yes
ssl = yes
ssl_cert = </etc/ssl/certs/server.crt
ssl_key = </etc/ssl/private/server.key

mail_access_groups=mail
mail_location = mbox:~/mail:INBOX=/var/spool/mail/%u
passdb {
  driver = pam
}
protocols = imap pop3
service auth {
  user = root
}
service imap-login {
  chroot = login
  user = dovecot
}
service pop3-login {
  chroot = login
  user = dovecot
}
userdb {
  driver = passwd
}

• Change permissions for the mail_location directory:

chmod 0600 /var/spool/mail/*

Start the server

/etc/rc.d/dovecot start