[unisog] Email and tcpwrappers

Julian Y. Koh kohster at northwestern.edu
Fri Apr 18 16:27:25 GMT 2003


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At 19:01 -0400 04/17/2003, John LaPrad wrote:
>We tried requiring rDNS but had to give it up. Many, many legitimate emails
>come from improperly configured servers. We even had some sys admins tell us
>that their security policy required them to have bogus rDNS info.

Yeah, blocking based on no/invalid rDNS is not a good idea for mail.  What
I've found to work rather well is to reject mail where the From: or Reply-To:
address does not have a domain name that at least has a valid MX record.  But
that won't catch most of the spam, honestly.

SpamAssassin, like others have mentioned, is working great on my server.


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-- 
Julian Y. Koh                             <mailto:kohster at northwestern.edu>
Network Engineer                                       <phone:847-467-5780>
Telecommunications and Network Services             Northwestern University
PGP Public Key:<http://charlotte.at.northwestern.edu/julian/pgppubkey.html>



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