nanog mailing list archives

Re: Misguided SPAM Filtering techniques


From: Dave Pooser <dave.nanog () alfordmedia com>
Date: Tue, 23 Oct 2007 19:45:34 -0500


I want to make it clear... I don't mind people filtering either 25 or
587, but, blocking both is highly unacceptable.

I can't see any operational reason to block 587.

Even more unacceptable
in my opinion is hijacking connections to either off to your own
man-in-the-middle attack server.

We had a client whose RFP vanished into thin air because of that-- he sent
it from a hotel that practiced port 25 hijacking and had had their IP
blacklisted for spewing much spam and viruses. So our server rejected the
message, and when it tried to send the NDN to him *his* server rejected the
NDN for the same reason. Fortunately he called the next day with some
details he'd omitted....

I recommended he go back with an army of Huns and raze the hotel, but he
settled for a nasty letter and using 587/TLS in future.
-- 
Dave Pooser, ACSA
Manager of Information Services
Alford Media  http://www.alfordmedia.com



Current thread: