Set up with Postfix, Postgrey, Dovecot, Cyrus SASL, ClamAV, SpamAssassin, Amavisd-new, and Fail2Ban on CentOS 6.4.

Here's [a great guide](http://www.shisaa.jp/postset/mailserver-1.html) (cached).

### Billy Gorbachev's options:

-   OpenBSD. Eliminates need for fail2ban, since pf has this
    functionality built in.
-   qmail, not Postfix.
-   OpenBSD spamd, not Postgrey. spamd hurts spammers more, and hurts
    legit senders less. logs are hilarious, e.g. 178.33.129.117:
    disconnected after 3995 seconds. lists: spamd-greytrap
-   Replace spamassassin with Spamhaus hooks in qmail (tcpserver).
-   qmail-pop3d, not Dovecot. Dovecot has a poor security track record.
    Download mail over (pop3 over CurveCP), using fetchmail + CurveCP
    command-line tools. Store locally in Maildir, backup
    as necessary/desired.
-   drop ClamAV and Amavisd. Run FreeBSD or OpenBSD on your desktop.
-   Add GnuPG to your local mail client.
-   Add Spamhaus DROP and eDROP to network edge pf tables
    <http://www.spamhaus.org/drop/>
-   Add a TXT SPF record for your domain, including your servers,
    followed by "-all"

Several of these changes can be made (SPF record, DROP, GnuPG) without modifying your existing setup.