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Re: incorrect spam setups cause spool messes on forwarders


From: Suresh Ramasubramanian <suresh () outblaze com>
Date: Mon, 01 Dec 2003 13:30:57 -0500


Randy Bush  writes on 12/1/2003 1:10 PM:

is the following a general problem, or just one i am seeing?

Verizon does SMTP callbacks, connecting back to the MX of the envelope sender and trying to verify that the user exists


2003-12-01 10:09:05 1APbBa-000Ork-DY == foo.user () verizon net <foo () psg com> R=lookuphost T=remote_smtp defer (0): SMTP 
error from remote mailer after MAIL FROM:<nikkiadamczyk () gerbangmail com> SIZE=5365: host relay.verizon.net 
[206.46.170.12]: 450 Requested mail action not taken-Try later:sc004pub.verizon.net


So this would connect to the MX of gerbangmail.com and try to verify that whatever () gerbangmail com exists.

gerbangmail.com.        5h55m6s IN MX   0 sitemail.everyone.net.

If the MX (sitemail.everyone.net) doesn't respond fast enough for verizon, their tester times out, and the message gets 4xx'd.

        srs

--
srs (postmaster|suresh)@outblaze.com // gpg : EDEDEFB9
manager, outblaze.com security and antispam operations


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