1. sudo yum install postfix spamassassin (spamassassin is optional and not covered here)\\
2.  sudo vi /etc/postfix/main.conf \\
uncomment the following line:
<code>
default_privs = nobody
</code>
change the following lines
<code>
myhostname = sf-lug.com
</code>
<code>
mydomain = sf-lug.com
</code>
<code>
myorigin = $mydomain
</code>
(make sure smtp listens on all interfaces (eth0, lo0...)
<code>
inet_interfaces = all
</code>
<code>
mydestination = $myhostname, localhost.$mydomain, localhost
</code>
(deny mail from other hosts -check me!)
<code>
mynetworks_style = host
</code>
<code>
 mail_spool_directory = /var/spool/mail
</code>

3. Change the following in /etc/hosts so mail will come from the right domain (sf-lug.com)
<code>
127.0.0.1               sf-lug.com localhost
</code>