Mail PTR Records

[Peter Farrow]

Glenn Steen wrote:
> On 03/03/2008, Matt Kettler <mkettler at evi-inc.com> wrote:
>   
>> Nathan Olson wrote:
>>  > It's not RFC-compliant.
>>
>>
>> Please point out the RFC and section it violates.
>>
>>  AFAIK, there's no section that prohibits refusing mail due to lack of PTR
>>  records for the IP address.
>>     
> It might be that Nathan interpretes the "address verification" bit as
> doing any form of DNS.... which actually might be the "spirit" of all
> that.... Hm.... Need sleep and time to think on this:-)
>
>   
>>  I've been proved wrong before, but I'm extraordinarily skeptical that there's
>>  any such restrictions in the RFCs.. I can find no mention of such a restriction
>>  in RFC 821, 2821 or 1123.
>>     
> :-) You're a big man, Matt.
>
>   
>>  On the contrary, RFC 1912 section 2.1 directly tells you that that not having a
>>  PTR record could lead to services refusing to talk to your hosts.
>>
>>  Also, RFC 1912 states that all IP address should have have a PTR record
>>  associated with them in the in-addr.arpa space.
>>
>>  So, the documentation I can find in the RFCs suggests that blocking connections
>>  from hosts which lack PTR records is legal and should be expected.
>>
>>     
> Interresting implications there...:-)
>
> Cheers
>   
Just bin the emails from ptr-A record mismatched hosts, then sell the 
ISP/user in question consultancy services to put it right...

Simple economics, turn someone elses config problem into a revenue 
opportunity.

If the sender is genuine they will want this fixed, if not, they are 
probably a spammer anyway.

P.