incorrect spam setups cause spool messes on forwarders

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 verizon.net <foo at psg.com> R=lookuphost T=remote_smtp defer (0): SMTP error from remote mailer after MAIL FROM:<nikkiadamczyk at 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 at 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