Folllow-up Test Code - Re: [Mimedefang] Potential for Businessmail servers to nothavereverse DNS

John Rudd john at rudd.cc
Thu Oct 5 21:45:51 EDT 2006


Kevin A. McGrail wrote:
> 
> I've taken a while to digest it for a more thorough response but really 
> only found one issue with the fundamental differences between our 
> approaches.
> 
>> b) I look for elements of the IP address in the domain (or, in the 
>> sub-domain in your case).
> 
> I would recommend against this because large vendors like 
> MCI/WorldComm/Verizon have gone with this naming scheme for business 
> static users:
> 
> static-70-21-118-207.res.east.verizon.net.
> 

My primary reaction to this is:

if their ISP wont give them a custom PTR record, then they should use 
their ISP's SMTP server for outbound email.  This is absolutely true, 
but lots of people bristle at the suggestion that their business mail 
server shouldn't talk directly to the world.  So, I've been considering 
moving those checks to filter_end and having it generate tags that 
indicate the message should be treated as spam instead of being rejected.



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