[Mimedefang] OT: DNS sanity check

John Rudd john at rudd.cc
Wed Jul 4 19:16:28 EDT 2007


Les Mikesell wrote:

> 
> Please show me where it says you _MUST_ accept from IP's that do have
> reverse DNS configured to match the A record before I go looking for an
> equivalent mandate for the case where they don't.   I don't believe
> either exists, and any decisions based on sender DNS lookups are
> entirely arbitrary, not standards-based.
> 


a) Correct, you are not required to accept any message.  You can always
reject them, evne if they have correct reverse DNS.  That doesn't
contradict anything I've asserted.  If anything, it agrees with what I'm
asserting: unless you are directed that you MUST, then you don't to.


b) They are not arbitrary, they are based upon best practices as stated
in the RFC I put into my first message in this thread.  It clearly
states that if you should have matching PTR and A records, and that if
you don't you should expect to have people refuse to deal with you.


My position on this is supported by a best practices RFC.  Yours isn't
even supported by the RFC sections you've quoted.





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