SpamAssassin-Milter accuracy...

Louis LeBlanc FreeBSD at
Tue Jan 4 09:09:23 PST 2005

On 01/04/05 05:17 PM, Matthias Buelow sat at the `puter and typed:
> Louis LeBlanc wrote:
> > Use with care.  Some spam rbls are overly zealous, and often block out
> > whole netblocks just because one IP has been reported as an offender.
> And all dialup networks.  Which can lead to the bizarre situation that 
> if you're relaying through your mail server from a dialup IP, and mail 
> goes thru SA, you'll get a high score.  There're several ways to prevent 
> this from happening, of course, for example, to run an extra smtpd on a 
> nonstandard port that doesn't push mails through SpamAssassin, or just 
> to disable the damn RBL stuff in the SA config (I did both, greylisting 
> is more effective than the suspicious RBL stuff anyways).

This includes most dynamically allocated IP blocks.  The only way to
avoid getting tagged and/or outright rejected by some networks is to
relay through the ISPs relay.

It's because of this that I don't use the spamblock RBLs at the MTA
level.  SA works almost perfectly with it's own clearing house checks
(NJABL, SORBS, SPAMCOP, etc.) and modifies the score for each.  I've
dug up some recipes that will further compound scores for multiple of
these clearing houses too, so you get bonus points for getting
reported to 3 or more :)

I do use the blackholes (check at the MTA, since
rejecting mail outright from Asian (and a few African) countries has
reduced my spam intake by about 80%, without reducing my legitimate
mail by a single message.  Since I'm not running a service for other
people, and I carefully choose the blackhole domains I use, it's not a
problem for me.  Of course, that may not be an option for you.
Someday I'll stop this practice, but for now some of my doors are just
plain closed.

Louis LeBlanc               FreeBSD at
Fully Funded Hobbyist, KeySlapper Extrordinaire :)                     Ô¿Ô¬

Volley Theory:
  It is better to have lobbed and lost than never to have lobbed at all.

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