Yes, in generally we're trying to encourage people to not use the ptr any
more than necessary.
In this case, converting a PTR to an IP list would have been unreliable to
say the least. We could have queried some of our fancy databases and got a
good idea of what IPs were yours, but it would not have been conclusive or
trustworthy. Dropping the PTR was really one of the major down sides to
using SPF in this fashion. Other wise it seems to be working quite well.
-Brian.
Brian Barrios
703.265.7456 / IM: BrianAntiSpam
Antispam/Postmaster Group - America Online, Inc.
-----Original Message-----
From: owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
[mailto:owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com] On Behalf Of wayne
Sent: Friday, November 19, 2004 4:00 PM
To: spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
Subject: Re: [spf-discuss] FW: Dynamic Senders List (aka SPF
Whitelist)
In <a0(_dot_)1bd4ba67(_dot_)2ecf9193(_at_)aol(_dot_)com> "Brian Barrios"
<brianantispam(_at_)aol(_dot_)com> writes:
SPF info:
http://postmaster.aol.com/spf/
About the Dynamic Senders List:
http://postmaster.aol.com/spf/about.html
Great info. I especially like the fact that you point out that ptr:
mechanisms can't be converted to IP addresses. While the ptr:
mechanism can be very useful in certain cases, in general, it isn't as
good a choice as other mechanisms. It is both more expensive and less
reliable.
Thanks again for your support of anti-spam systems, including SPF.
-wayne
-------
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