Milter-greylist

Hello,

it appears that Milter Greylist and Postfix's address verification are
two spam fighting technologies which love to fight each other. What
happens is this:

1.) An e-mail server using Milter Greylist tries to deliver an e-mail
    to an Postfix instance configured to use address verification.

2.) The Postix instance connects back to the e-mail server using
    Milter Greylist and cannot verify the e-mail address because
    greylisting is active.

3.) The Postfix instance refuses to accept the e-mail because the
    address verification has failed.

Is there anything which can be done about this? My guess is that the problem
would not occur if Milter Greylist would refuse the e-mail at the "DATA"
instead of the "RCPT" stage. Is that possible?

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/

On Thu, Jul 15, 2004 at 02:45:29PM +0200, Matthias Scheler wrote:
> Is there anything which can be done about this? My guess is that the problem
> would not occur if Milter Greylist would refuse the e-mail at the "DATA"
> instead of the "RCPT" stage. Is that possible?

The solution is to introduce a special case for mail from <> and reject
it after the DATA command instead of RCPT. Rejecting all mail at DATA is
not a good idea since it will give more work to other milters that do 
content filtering.

I plan to add this, but we have two huge patches to integrate first: Full
IPv6 support and selectable bind address for mxsync.

-- 
Emmanuel Dreyfus
manu@...

On Thu, Jul 15, 2004 at 12:49:20PM +0000, Emmanuel Dreyfus wrote:
> The solution is to introduce a special case for mail from <> and reject
> it after the DATA command instead of RCPT. Rejecting all mail at DATA is
> not a good idea since it will give more work to other milters that do 
> content filtering.

Postfix doesn't use an empty sender it uses "postmaster@...":

Jul 15 12:30:36 colwyn milter-greylist: i6FAUZUb011843: addr x.x.x.x from <postmaster@...> to <matthias@...> delayed for 00:29:00
Jul 15 12:30:36 colwyn sm-mta[11843]: i6FAUZUb011843: Milter: to=<matthias@...>, reject=451 4.7.1 Greylisting in action, please come back in 00:29:00
Jul 15 12:30:36 colwyn sm-mta[11843]: i6FAUZUb011843: from=<postmaster@...>, size=248, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=xxx.xxx.xxx [x.x.x.x]

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/