spf-discuss
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Re: PTR records that do not have forward mappings

2003-11-30 16:03:28
Cable Users with dynamic IPs are will proably be listed in a dynRBL and
will have a difficult time doing direct delivery... do it on your own
risk.

not having a mathich forward entry to a reverse entry fails RFC1912

On Sun, Nov 30, 2003 at 11:08:39 -0500, Philip Gladstone wrote:
I have a script that has been working out SPF records for domains, and 
I've noticed that some of them are more complex than desirable owing to 
the lack of forward mappings from name to ip. In particular, this often 
happens for the names that are the result of a reverse lookup.

Consider a user who is on a DHCP cable modem network. They want to be 
able to send mail directly out. However, owing to the DHCP nature of 
their connection, they can only restrict their sending addresses to the 
ISP. But the ISP just assigns names to those DHCP addresses that do not 
have forward mappings. For example:

For example:  200.232.161.241 maps to 200-232-161-241.dsl.telesp.net.br. 
but this latter name is NXDOMAIN

This makes it difficult for the end user to select a suitable SPF 
record. Maybe those ISPs need educating.....

Just an observation

Philip
--
Send mail to spftest(_at_)gladstonefamily(_dot_)net to get your SPF record 
automatically reviewed



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