[Mimedefang] the right place to put greylist check?

[David F. Skoll]

On Sun, 11 Jan 2004, Kenneth Porter wrote:

> I wonder if it makes sense to tempfail at helo if you've never seen the
> relay before, and then do regular greylisting in a subsequent phase? On a
> busy server, that could cut a lot of load.

Unless the sending server is deliberately holding the connection open,
I can't see too much benefit from that.

> > Be aware of one more factor: Some buggy MTA's (Novell Groupwise for
> > one, I believe, and ancient versions of SLMail from Seattle Labs) fail
> > if all RCPT commands are tempfailed, and bounce (rather than queuing
> > and retrying) the message.

> Is Novell doing anything to fix that?

I don't know; I haven't confirmed 100% that GroupWise has the bug.  I
did confirm it with an old version of SLMail, and Seattle Labs
informed me that the bug is fixed in newer versions.

> How hard is it to identify these MTA's when they come knocking? Can
> they be spotted in Received lines?

But you don't have a Received: line until the DATA phase. :-)

As far as I can see, it is not possible to identify such buggy MTA's in
time to do any good.

Regards,

David.