Noel Sanchez wrote:
>> Que te pasa con sendmail
>> ___________________________________
If you haven't already, take a look at ORDB lookups done with Sendmail.
This should be the first level of a multi-layer anti-spam approach for
any Sendmail installation.
Custom Rolled IP Tables Firewall Ruleset (Firewall - Layer 1)
- Use Geo-blocking: deliberately blocking port 25 traffic, at the
very least, entire netblocks where SPAM is known to originate
from. (email me off-list and I can send you a collection of
bash and perl scripts I use to both create rulesets
and refresh the IP tables rules being used in my Firewall
running on my mailserver.)
Sendmail (MTA Level - layer 2)
- configure sendmail to cause it to do ORDB lookups from
any one of many very dependable ORDB's such as SpamCop
to check to see if the IP listed in the headers exists
in the ORDB database.
SpamAssassin (MTA Level - Layer 2)
- Setup SpamAssassin, configure it and start using this
critter; not as a first and only line of defense, but as
part of a layered approach to controlling the amount
of SPAM reaching your network and users.
Administrator Diligence (Application Level - Layer 3)
You're never going to stop it all - the best you can hope for is to
reach a state of equilibrium. Once you reach that state you should only
see a spike now and then, but expect at least 5-7 SPAM per user per
week. Diligence in keeping the filters updated is Key.
--
Mark
"If you have found a very wise man, then you've found
a man that at one time was an idiot and lived long enough
to learn from his own stupidity."
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