incorrect spam setups cause spool messes on forwarders

Suresh Ramasubramanian suresh at
Mon Dec 1 18:30:57 UTC 2003

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 at <foo at> R=lookuphost T=remote_smtp defer (0): SMTP error from remote mailer after MAIL FROM:<nikkiadamczyk at> SIZE=5365: host []: 450 Requested mail action not taken-Try

So this would connect to the MX of and try to verify 
that whatever at exists.        5h55m6s IN MX   0

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


srs (postmaster|suresh) // gpg : EDEDEFB9
manager, security and antispam operations

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