Next Previous Contents

2. Mail Transfer Agent

The MTA is a program that sends mail from one server to another. This is done through the SMTP protocol. On Debian the default MTA is Exim, however there are several GNU/Linux servers that contain this functionality like: sendmail, postfix and qmail.

I like postfix so let's start with that one.

2.1 postfix

Next to it's MTA functionality we also use it's MDA functionality by using the Maildir format for mail storage. Keep in mind that all mail for a user, when using Maildir, is stored in his/her home directory. This will grow the size of peoples home directory.


apt-get install postfix

Choose Satellite system when asked for configuration and supply what is needed.


The postfix configuration files can be found in /etc/postfix/.

The most important file is Elements in this file that need special attention:

myhostname =
mydestination = $myhostname, localhost.$mydomain, $mydomain
mynetworks =,
relay_domains = $mydomain
home_mailbox = Maildir/


Test the configuration with telnet:

telnet localhost 25            # from the local machine
telnet 25       # from a Internet machine
telnet 25          # from an internal machine

Use the following procedure:

mail from:
rcpt to:

Next Previous Contents