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