At 10:43 AM 11/29/2004 -0500, Alex van den Bogaerdt
<alex(_at_)ergens(_dot_)op(_dot_)het(_dot_)net> wrote:
On Fri, Nov 26, 2004 at 02:35:51PM -0700,
administrator(_at_)yellowhead(_dot_)com wrote:
Once again I will point out the problems of verifying mail based on PTR
records, only this time I have a very good example.
Er, this is the SPF list, not the PTR list ?
*************** REPLY SEPARATER ****************
This topic has been discussed many times on this list, and is definitely
relevant. As long as there are those that would use reverse lookup to
verify email (SPF has so far side-stepped the issue for the most part), the
potential is there to run into problems like these. The domain owner is
probably not even aware of this problem, although I have tried to bring it
to their attention. Because the reverse lookup process is a top down driven
process, it is sometimes very difficult to get the upstream ISP to resolve
the issue, and in the meantime email could be getting waylaid.
I was simply trying to reiterate how dangerous it is to use PTR records for
verifying email sources, and I apologize to those that might think it
off-topic.
J.A. Coutts