We regularly create pieces of code to get something done. Some of that code is published here so that others may use it.
A lot of this stuff makes up parts of our mail cleansing, and it does a great job.
Most of the bad stuff is stopped before the system has to actually examine the received mails, wich saves a lot of CPU, while most of the good stuff is accepted without delay.
We are using MIMEDefang with an advanced filter, ClamAV and SpamAssassin with plugins to make this as effective as we can.
The asasmtpd is a strange authenticating SMTP daemon that uses our POP servers as backends for authenticating our users when they send mail from outside our LAN.
The proxy filters is a filter config for apache that stops a lot of worms and exploits at out reverse proxy. This is not a safe security measure, but rather a way to lessen the load on our web servers.
(2006-11-21)