Wed 2008-03-05 01:09:52: Session 2883; child 2; thread 1604 Wed 2008-03-05 01:09:51: Accepting SMTP connection from [184.108.40.206 : 13532] Wed 2008-03-05 01:09:51: Looking up PTR record for 220.127.116.11 (18.104.22.168.IN-ADDR.ARPA) Wed 2008-03-05 01:09:51: D=22.214.171.124.IN-ADDR.ARPA TTL=(1440) PTR=[ug-out-1314.google.com] Wed 2008-03-05 01:09:51: Gathering A-records for PTR hosts Wed 2008-03-05 01:09:52: D=ug-out-1314.google.com TTL=(1440) A=[126.96.36.199] Wed 2008-03-05 01:09:52: Reverse lookup configured to drop connection on PTR record miss-match. Wed 2008-03-05 01:09:52: --> 501 Domain must resolve Wed 2008-03-05 01:09:52: 0 bytes transferred
I post this in the hope that someone from gmail might actually stumble by. It has been reported to the dns administrator for google.com already.
As you can see from the above log snippet, the A and PTR records for the particular gmail.com server connecting to deliver a message do not match in the last octet.
This is *common* to multiple gmail servers connecting from multiple /24 networks. Whitelisting them is a royal pain in the you know what.
The reality is that if google/gmail does not fix this, then the volume of users forces the whitelisting or abandoning a useful spam test. While it might be a fact of life, giving special treatment to the googlrilla makes me grind my teeth.