Author: Steve Thomas Date: To: exim-users Subject: Re: [Exim] ACL config to reject mail from non standard DNS mailers
On Fri, Feb 27, 2004 at 10:39:09AM -0600, mark david mcCreary is rumored to have said: >
> seems like a marvelous idea, until I saw
> ...
So you'd reject mail from my server, which is hosted on a RoadRunner business connection (resolves as *.rr.com), is not a source of spam and properly identifies itself as chips.sthomas.net (A record exists for that hostname)? I think you'll find that there's a whole bunch of legitimate reasons that the HELO wouldn't match the PTR and IIRC, no RFCs are being violated with that configuration.
I see where you're coming from, but there's a LOT of businesses hosted on networks for which they have no control over the PTR records.
A better idea (IMHO) would be to do a forward lookup on the HELO hostname and see if the result matches the IP they're connecting from. Even that's flawed, though, as it doesn't take NAT'd boxes into account..
--
"I am ready to meet my Maker. Whether my Maker is prepared for the great ordeal of meeting me is another matter."
- Sir Winston Churchill (1874-1965)
