| Sanford Whiteman 2007-07-05, 7:18 am |
| > What is the point of this checkbox? I was hoping it meant that the
> SMTP server would reject connections where RDNS failed.
Yes, we all had that hope once. 
It'll _tag_ messages that have a non-empty HELO that doesn't match the
empty or non-empty PTR, but it won't reject them at the connection
level. To do more than that, you'd need an event sink that does more
connection-time processing.
IMO, it's in a sense good that such an easy-to-flip feature doesn't
reject all roundtrip failures without any means of whitelisting. As
effective as the roundtrip test has proven to be, being able to ignore
it for V.I.P./sloppy-yet-legit servers is essential. With tagging, at
least you could interpret the roundtrip failure in a post-acceptance
anti-spam system that itself offers whitelisting (though that system
might do the lookup itself just as easily, and post-acceptance
weighting of data that was wholly available pre-acceptance is
backward).
--Sandy
|