SUNScholar/Prepare Ubuntu/S07/Advanced

Back to Step 07

If you are satisfied with the installation of Postfix, you may skip this step. Otherwise continue below.

To review the Postfix main.cf file, type as follows:

sudo nano /etc/postfix/main.cf

Tip: It is always a good idea to maximise the open nano window so that the copy and paste of long lines does not wrap around.

See below for an example of the config file:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version


# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/%hostname%.pem
smtpd_tls_key_file=/etc/ssl/certs/%hostname%.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

myhostname = %hostname%
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = %hostname% localhost
relayhost = %relay-hostname%
mynetworks = %my-subnet% 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

1. Change the %hostname% to the hostname of your server.
2. Change the %relay-hostname% to the hostname of your campus email server which sends and delivers email.
3. Add the subnet of your campus TCP/IP network %my-subnet% to the mynetworks parameter.
4. Ensure mydestination = %hostname% localhost to prevent your mail server becoming a spam email relay.

Talk to the campus system administrator about these settings.

Also see: http://www.postfix.org/SMTPD_ACCESS_README.html and http://en.wikipedia.org/wiki/Subnet_Mask.

The postfix server can be re-configured by typing the following:

sudo dpkg-reconfigure postfix