[Gllug] E-Mail screening and reverse DNS

[Ken Smith]

Paul Cupis wrote:

>Nix wrote:
>  
>
>>On Sun, 11 Jun 2006, Paul Cupis yowled:
>>    
>>
>>>Ken Smith wrote:
>>>      
>>>
>>>>My guess is that the IT dept at the remote site have set up some
>>>>rigorous reverse DNS validation. The reverse DNS for here will be
>>>>ksmithdsl.claranet.co.uk. So the reverse DNS for my locally hosted
>>>>domain won't check out. My outgoing e-mail goes directly and not via
>>>>Clara's SMTP server.
>>>>
>>>>So my question is: how is this dealt with?
>>>>        
>>>>
>>>Fix your reverse DNS so it matches your forward DNS?
>>>      
>>>
>>Why should it need to do that? Sites rejecting SMTP connections
>>where forward != reverse DNS (as opposed to those where forward and
>>reverse do not resolve to the same IP) will reject a very large
>>proportion of legitimate mail, including mail from many *major*
>>mailing lists.
>>    
>>
>
>OTOH I notice that today:
>
>$ host ksmithdsl.claranet.co.uk
>ksmithdsl.claranet.co.uk        A       80.168.136.138
>$ host 80.168.136.138
>Name: ksmithdsl.claranet.co.uk
>Address: 80.168.136.138
>
>which matches - the impression I got was that this was not the case when
>the OP posted (though I didn't check).
>
>  
>
Today Clara have fixed the rDNS so:-


$ host 80.168.136.138
138.136.168.80.in-addr.arpa domain name pointer knetgate.kensnet.org.
$ host knetgate.kensnet.org
knetgate.kensnet.org has address 80.168.136.138


Ken

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