This guide will show you how to setup Postfix mail server running alongside Cyrus SASL, Courier-IMAP and SquirrelMail. Once everything is setup you will be able to read and write emails using the SquirrelMail web interface and be able to access your email anywhere in the world!

Install and Configure Postfix
Postfix requires a DNS service running otherwise it will not work, follow this Debian Lenny Bind Howto guide if required. During the Postfix installation, Select ‘Internet Site’ and enter your domain name for ‘System mail name’, ie example.com

# aptitude install postfix

Make sure you read the comments and change accordingly.

# vim /etc/postfix/main.cf

smtpd_banner = $myhostname ESMTP $mail_name (example.com)
biff = no
append_dot_mydomain = no

### your hostname here
myhostname = server   

mydomain = example.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $mydomain, localhost.$mydomain, localhost

### your allowed networks
mynetworks = 127.0.0.0/8,192.168.1.0/24   

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $mydomain
broken_sasl_auth_clients = yes

smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination

home_mailbox = Maildir/
alias_maps = hash:/etc/aliases

### your ISP SMTP relay
relayhost = relay.yourisp.net

smtpd_recipient_limit = 250

readme_directory = /usr/share/doc/postfix
html_directory = /usr/share/doc/postfix/html

Setup Postfix SASL Authentication

# vim /etc/postfix/sasl/smtpd.conf

pwcheck_method: saslauthd
mech_list: plain login

Aliases are used to map names with email accounts. This example will map all mail for root with ‘you@example.com’. You can add as many aliases as you like, ‘my.nick’ and ‘my.name’ are just examples.

# vim /etc/aliases

postmaster:    root
root:   you@example.com
my.nick:  you@example.com
my.name:  you@example.com

# newaliases

Install SASL Authentication
Edit saslauthd and change ‘START=yes’, dont touch the rest of the configuration.

# aptitude install sasl2-bin libsasl2-2 libsasl2-modules
# vim /etc/default/saslauthd

START=yes

We need to make sure chrooted Postfix can communicate with saslauthd.

# rm -r /var/run/saslauthd/
# mkdir -p /var/spool/postfix/var/run/saslauthd
# ln -s /var/spool/postfix/var/run/saslauthd /var/run
# chgrp sasl /var/spool/postfix/var/run/saslauthd
# adduser postfix sasl

Install Courier-IMAP
During the install process it will ask ‘Create directories for web-based administration?’ say No.

# aptitude install courier-imap
# vim /etc/courier/authmodulelist

authdaemon

Install Squirrelmail

# aptitude install squirrelmail
# ln -s /etc/squirrelmail/apache.conf /etc/apache2/conf.d/squirrelmail.conf
# ln -s /usr/share/squirrelmail /var/www/squirrelmail
# chgrp -R www-data /usr/share/squirrelmail/

Add User and Setup Mailbox
You will be asked for user ‘you’ password, make sure you remember this password as this account will be used to access your email.

# adduser you
# su you
$ maildirmake.courier /home/you/Maildir

Start Postfix, Cyrus SASL, Courier-IMAP and Apache

# /etc/init.d/postfix start
# /etc/init.d/courier-imap start
# /etc/init.d/courier-authdaemon start
# /etc/init.d/saslauthd start
# /etc/init.d/apache2 restart

Test Postfix SMTP with Telnet
This will create a string for SASL authentication, don’t forget to insert ‘0′ when they are needed.

# perl -MMIME::Base64 -e 'print encode_base64("you0you0yourPASSWORD");'

eW91AHlvdQB5b3VyUEFTU1dPUkQ=

Now we can telnet into the Postfix SMTP server and send a test email. Type in the commands in the places where I have indicated ‘<<<'

# telnet 192.168.1.20 25

220 debian ESMTP Postfix (example.com)
EHLO LOCALHOST   <<<
250-debian
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
AUTH PLAIN eW91AHlvdQB5b3VyUEFTU1dPUkQ=   <<<
235 2.7.0 Authentication successful
MAIL FROM:<you@example.com>   <<<
250 2.1.0 Ok
RCPT TO:<you@example.com>   <<<
250 2.1.5 Ok
DATA   <<<
354 End data with .
THIS IS A TEST MESSAGE!!   <<<
.   <<<
250 2.0.0 Ok: queued as 832291812D
QUIT
221 2.0.0 Bye

Check Squirrelmail
Fire up, http://example.com/squirrelmail and log in as the user ‘you’ we created previously, hopefully you should see the test email we sent using telnet! You should now be able to send and receive email. Make sure the MX record in your registered domain name is pointing at your box, and you have forwarded port 25 on your firewall.