Dovecot

Configuring Dovecot

/etc/dovecot/dovecot.conf

The following lines will need to be uncommented and if necessary changed to reflect your plans for the environment :

protocols = imap pop3

mail_location = maildir:~/Maildir

protocols - specifies the protocols that are available for users to access their email

mail_location - specifies the format and the location of each user’s mailbox

Authentication process file

This config file can be located at /etc/dovecot/conf.d/10-auth.conf

The following line will need to be uncommented and change if necessary

auth_mechanisms = plain login

auth_mechanisms = specifies the way in which the email client authenticates with Dovecot

Mail Location

to set the location for your mail, use the configuration file at /etc/dovecot/conf.d/10-mail.conf

Either add or uncomment the following line in the configuration file:

mail_location = maildir:~/Maildir

Postfix smtp-auth

change the configuration file to configure the unix socket for postfix smtp-auth. This can be found at /etc/dovecot/conf.d/10-master.conf

Comment out the following lines first

#unix_listener auth-userdb {

#mode = 0600

#user =

#group =

#}

Postfix smtp-auth

Now edit these lines in the same file.

# Postfix smtp-auth

unix_listener /var/spool/postfix/private/auth {

mode = 0666

user = postfix

group = postfix

}

POP3 Configuration

now we need to configure the pop3.conf file. This will allow some older or lesser-used email clients to connect and transmit correctly. This file can be found at /etc/dovecot/conf.d/20-pop3.conf

We will now need to uncomment or add the following lines.

pop3_uidl_format = %08Xu%08Xv

pop3_client_workarounds = outlook-no-nuls oe-ns-eoh

Creating a Mailbox

Now create an example mailbox for a user John Doe (john.doe) to send and receive emails.

You will need to create a user for this example

# useradd john.doe

then create the mail directory for the user

# mkdir /home/john.doe/Maildir

Then give john.doe ownership of the mailbox we just created by changing its permissions

# chown john.doe:john.doe /home/john.doe/Maildir

# chmod -R 700 /home/john.doe/Maildir

Starting Dovecot

Once you have finished creating the mailbox you will need to make sure the Dovecot application will be run with the server upon restart. You can use chkconfig for this.

# chkconfig --level 345 dovecot start

then you will need to start the service

# service dovecot start

Postfix configuration

Now you will need to go over the Postfix directories and make the following changes in the main.cf file. We do this so that we can allow our email client to connect to our newly built SMTP server.

Add the following lines to /etc/postfix/main.cf

smtpd_sasl_auth_enable = yes

smtpd_sasl_security_options = noanonymous

smtpd_sasl_local_domain = $myhostname

smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks, reject_unauth_destination

broken_sasl_auth_clients = yes

smtpd_sasl_type = dovecot

smtpd_sasl_path = private/auth

Once done you will need to restart the postfix service

# service postfix restart

Iptables port additions

Now that you have enabled secure SMTP ‘SSL’ we should allow connections to port 587 by opening the port in iptables for the server. Add the rules for this port by entering the following command:

# iptables -I INPUT 2 -p tcp --dport 587 -j ACCEPT

Iptables port additions

After adding the SSL SMTP port we should also add the POP and IMAP ports along with their secure counterparts.

# iptables -I INPUT 3 -p tcp --dport 110 -j ACCEPT

# iptables -I INPUT 3 -p tcp --dport 143 -j ACCEPT

# iptables -I INPUT 3 -p tcp --dport 993 -j ACCEPT

# iptables -I INPUT 3 -p tcp --dport 995 -j ACCEPT

Once these lines have been added you should save the iptables rules and restart iptables

# /etc/init.d/iptables save

# /etc/init.d/iptables restart