[Techtalk] opinions on RBLs, please

[Kelly Martin]

Carla Schroder wrote:
> In my never-ending quest for good spam-fighting tools, I've been pondering 
> using RBLs. However I'm concerned about blocking legitimate emails, they seem 
> rather cavalier about the possibility. "If your ISP is a spammer, get a 
> different ISP." Anyone have experience with them? There won't be any relaying 
> issues for my clients, no downstream servers, just how will their own mail 
> delivery be affected.

Just as an additional data point: most porn spam is sent from 'owned' 
boxes.  These are often on dynamic IP addresses, and the people doing it 
move from box to box to evade blacklisting.  By the time you identify 
the source to blacklist it, the spammer will likely have moved on, so 
that's a losing battle.

Commercial spam is more likely to have come from a spamhaus; those 
places do have fixed address blocks and can be blocked with some 
reliability.  Unfortunately, the commercial spam is not the most 
annoying variety.  It's the porn spam that irks people the most, and 
it's the hardest to stomp on precisely because of the manner in which 
they do business (that is to say, illegally).

Kelly