[65523] in North American Network Operators' Group
Re: incorrect spam setups cause spool messes on forwarders
daemon@ATHENA.MIT.EDU (Jared Mauch)
Mon Dec 1 14:11:55 2003
Date: Mon, 1 Dec 2003 14:03:33 -0500
From: Jared Mauch <jared@puck.nether.net>
To: Randy Bush <randy@psg.com>
Cc: Suresh Ramasubramanian <suresh@outblaze.com>, nanog@nanog.org
In-Reply-To: <E1AQt8G-0002Qk-2F@ran.psg.com>
Errors-To: owner-nanog-outgoing@merit.edu
On Mon, Dec 01, 2003 at 10:50:51AM -0800, Randy Bush wrote:
>
> >> 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.
>
> interesting but utterly irrelevant. the question was not how
> verison decided it was spam. the point was that their server
> returned a 450 as opposed to a 5xx (550 looks good), and this
> causes net damage.
I think he's saying that they were unable to perform
the validation hence the 450. If the validation was successful,
they'd return a 200 series code, if it was unsuccessful, they
would return a 500 series code.
- jared
--
Jared Mauch | pgp key available via finger from jared@puck.nether.net
clue++; | http://puck.nether.net/~jared/ My statements are only mine.
