[Mimedefang] OT: DNS sanity check

[Jeff Rife]

On 4 Jul 2007 at 17:06, John Rudd wrote:

> Your counter-assertion against this behavior is completely unfounded.
> There is nothing that says you MUST NOT nor SHOULD NOT reject based upon
> the sender's bad DNS (the only prohibition that comes close is based
> upon the sender's bad HELO).  A sender who doesn't have matching A and
> PTR records is violating best practices.  It is perfectly reasonable to
> reject a sender's email when you know they're violating best practices.

No, it's not "reasonable".  It's certainly allowed, but it's not at all 
reasonable, because those same "best practices" that you are using as 
your holy grail have also always said:

  "Be liberal in what you accept, and conservative in what you send"

Unless the lack of DNS (or lack of correct DNS) is a show-stopper in 
your processing, I'd say that not rejecting e-mail based on a DNS 
inconsistency is absolutely the most reasonable thing to do.


--
Jeff Rife |  
          | http://www.nabs.net/Cartoons/BabyBlues/TVDistance.gif