GWIA question for y'all

Mike Gerzema MGERZEMA at
Mon Jul 23 18:27:50 UTC 2001

I've tried it as well with similar results. Some of our customers ISPs have tried as well and failed miserably. 

You're right there are very few reverse lookups setup, and if there are they usually point to the ISP. Our ISPs are very reluctant to point them to us since they are "their IPs". Maybe we'll have to buy our own. Anyone know of a class C for sale? ;-)

>>> tom.stone at 7/20/01 17:12:44 >>>
I, for one, have had almost no success implementing the "Reject Mail if
Senders Identity cannot be Verified" option.  It is not that the feature
doesn't work, it is that hardly anyone out there has their PTR record
configured for their mail server.  Every client of mine that has turned that
feature on has ended up turning that feature off because their outside
customers had about a 45% fail rate for inbound mail.  In other words, about
45% of the customers that they dealt with either had stupid ISPs or stupid
network administrators that didn't know how reverse DNS lookups work and
didn't know how to configure them.  

I argued with the administrator of a state-wide law firm once about this.
He accused ME of making him change HIS system because of a change I made on
MY mail system.  I tried to explain the issues regarding spam, relaying,
that there is an RFC out there, ORBS lists, etc., and all he would do is
harp on the fact that HE would have to change HIS system just to match MY
personal whim.  The final straw came when we found that the State Bar
Association wasn't configured properly.  We gave up at that point and put it
back to not verifying the sender's identity.

I am not sure if the proposed changes would help in these situations.  I
think that the changes are probably a step in the right direction but the
real problem lies in the lack of knowledge about DNS configuration among
people who should know better.  I suggest that we "whack em' upside the head
with a 2x4" first, just to get their attention, and also include
documentation on what a PTR record is for, how to configure them on common
systems, and why we want them configured.

Tom Stone
Goliath Networks, Inc.
tom.stone at 

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