[ale] Spam prevention

[Fulton Green]

On Thu, Jun 29, 2006 at 05:37:33PM -0400, David Corbin wrote:
> I've been using Spam Assassin for years, but I'm really getting a bit 
> disappoitned with it.  I easily have 30 plus SPAM that get through a day, and 
> a fair number of "false positives".
> 
> Is there a better Spam solution out there these days?

Besides the currently-in-testing Google Mail for Domains?  OK, seriously:

First off, you may want to explore tweaking the scores of the various
flags and / or the spam threshold, to take care of the false positives.
For the spams that are passing through, read below:

I have seen that SpamAssassin works best when used in conjunction with 
various blackhole lists.  They usually require a subscription fee.
However, some hosting providers (such as the one I'm with) simply roll in
the service fees into your account fee.  So what you'll get is a set of
additional SpamAssassin flags that indicate which blackhole lists raised
their flag.

Most blackholes examine either the sender IP address to see if it's in a
dynamic pool and / or was recently reported to be spamming.  Some
blackholes will also examine content.  True, SpamAssassin has a
traditional strength with text-based content examination, but newer
obfuscation techniques (HTML trickery, embedded images) are meeting with
greater success by the spammers.

The only real issues I've seen with false positives after using those
techniques seem to be with lists I've opted into (e.g., BusinessWeek).
However, when I asked one of the blackhole maintainers about it, they
claimed that the lists in question weren't dropping "test emails" that
requested opt-opt.