[Mimedefang] OT: DNS sanity check

[Les Mikesell]

John Rudd wrote:
> Les Mikesell wrote:
> 
>> And section 4.1.4 says:
>>
>>    "An SMTP server MAY verify that the domain name parameter in the EHLO
>>    command actually corresponds to the IP address of the client.
>>    However, the server MUST NOT refuse to accept a message for this
>>    reason if the verification fails: the information about verification
>>    failure is for logging and tracing only."
>>
>> But, since you are dealing with someone who isn't following the RFC's
>> anyway, you probably aren't going to get it changed on the receiving
>> end.  Your ISP should either delegate reverse DNS to you or handle it
>> for you, or provide a forwarding SMTP server, or both.
>>
> 
> Or maybe you're just not reading what's written.
> 
> They aren't rejecting based on bad HELO information.  They're rejecting
> based on bad DNS information.  Two entirely different things.
> 
> The OP hasn't even said word one about what's in the HELO information,
> and whether or not that's valid.
> 
> The ISP's statement has nothing to do with HELO information, and
> everything to do with PTR an A record information.
> 
> So, clearly, your claim that they're not following RFC's is unsupported.

And you seem to have avoided reading the other part of what I quoted
saying how hosts that are not in DNS _at all_ are permitted with special
dispensation in the syntax.  I don't see how anyone who has read that
can claim that is a requirement for forward or reverse DNS support at
the sending host.

-- 
  Les Mikesell
   lesmikesell at gmail.com