This is an autoblacklist for worms attacks.

When amavis scan a mail positively for virus (you could add spam too), block
the ip for a short amount of time (5min).

So that i don't get those brute force Netsky virus (just one).

The good thing is that it doesn't exclude anybody in particular like dynmic ip
ranges.

 Name                    Last modified      Size  Description
 Parent Directory                             -   
 HEADER.html             10-Dec-2004 22:11  330   
 dynablock.py            27-Apr-2004 09:28  3.3K