Being RFC-ignorant... Hi list,

I'm currently considering ways to deal
with customer spambots, putting our SMTP-IPs
every now and then on several blacklists
and would appreciate some input on this.

Aside from forcing everyone to use SMTP-AUTH,
which trails a ton of support, I'm thinking
about rate limiting or using a cidr-whitelist
in combination with a regexp-blacklist,
allowing only valid sender addresses for the
corresponding domain, permitting a defined
range of IP-addresses, rejecting every
other mail.

The user-syntax we're using nicely bypasses
like 90% of all the spam generated by our
customers. I ran a warn_if_reject and the
regexp works quite well; there were no
apparent false positives.

Is there, aside from the rfc-ignorance,
anything to worry about or something else
that would make this endeavour a rather
painful experience in whatever way?

Any clues or input appreciated.

Best regards,

sven03

Mit freundlichen Gruessen

i. A. Sven Juergensen

-- 
Fachbereich
Informationstechnologie

KielNET GmbH
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