[CALUG] help with dns reverse PTR record problem

[Duane Tucker]

Hi all,

I'm looking for someone who would be willing to help me with a DNS 
problem. I'm willing to pay for your time.

Background: I administer the network and servers for a small company. I 
have a linux server running postfix for outgoing smtp email. The domain 
is registered with godaddy and I use the godaddy DNS Manager tool for 
dns control.

The problem is this: when someone inside the network attempts to email 
anyone at a comcast.net address,  Comcast rejects the emails with the 
following message:

Nov 28 20:18:17 mailserver postfix/smtp[10207]: 4F0E36FD08: 
to=<teset at comcast.net>, relay=mx1b.comcast.net[76.96.62.116]:25, 
delay=19637, delays=19636/0.08/1/0, dsn=4.0.0, status=deferred (host 
mx1b.comcast.net[76.96.62.116] refused to talk to me: 554 
imta04.westchester.pa.mail.comcast.net comcast 69.85.36.83 Comcast 
requires that all mail servers must have a PTR record with a valid 
Reverse DNS entry. Currently your mail server does not fill that 
requirement. For more information, refer to: 
http://help.comcast.net/content/faq/PTR)


Comcast is the ONLY domain in almost 2 years that we have this problem 
with. Luckily, we almost never need to email anyone with a Comcast 
address. This problem has reared its ugly head only 3 or 4 times. It 
drives me nuts, however, that I can't figure out how to fix the problem. 
This weekend I even stumbled through setting up my own DNS server, using 
bind, but then couldn't figure out how to implement it. The reason for 
my confusion here is that in the godaddy dns manager, it requires me to 
enter a FQDN for the name servers, not an IP address. Well, if the 
purpose of the DNS server is to resolve names, and the DNS server is 
running within the same domain that your trying to resolve, how in the 
world would it ever get there for resolution?!?

Now you would think that the answer would be easy. Since I'm managing 
dns entries with the godaddy dns manager, why not just put a reverse PTR 
record there? But no, that's just too easy. Godaddy doesn't allow you to 
enter PTR records. They do have some perverted way to enter TXT records 
with a PTR embedded, but I can't figure that out either. When I called 
godaddy tech support, they politely informed me that since I don't use 
their hosts, they can't provide support for the dns entries. Sigh. By 
the way, here is a link to a godaddy support page discussing the 
TXT/PTR/SPF "thing".

http://community.godaddy.com/help/article/680

So if anyone reading this thinks they can help, please do let me know. 
I'm tired of spending weekends now and then chasing my tail. I know just 
enough about all this to be dangerous. The answer could be just one 
small step away and I simply can't see it.

Many thanks,
Duane Tucker