From: jschueler_at_tqis.com (email_suppressed_at_lugwash.org)
Date: Wed 21-Jan-2009 05:26:56 PM EST
One way to test for "spoofed" email is to ensure that the domain name of the
sender matches the sending machine.
But to accomodate mail relays,a validity tester simply ensures that the
forward and reverse DNS record match for the domain name of the sender.
Another exception is virtual mail hosts- one of many techniques to use an
email address ([e-mail suppressed]) without having a mail server dedicated to
that domain. To accomodate virtual hosts, the domain name of the envelope
sender is DNS tested instead of that of the header sender.
Over the years, I've successfully managed mail servers based on this
understanding. But now, trying to debug problems with Gmail, I've concluded
that Gmail is actually testing the domain name of the header sender. I sent
two messages, one flagged as Gmail spam. The only difference was the header
sender. The domain without a matching reverse pointer got flagged.
The guidelines imply header sender testing:
https://mail.google.com/support/bin/answer.py?answer=81126
One of the touted features of Gmail is their virtual server capabilities.
A non-fanboy might conclude they are restraining their competitors.
The way I interprete their docs: Google's workaround is that header senders
succeed if they can be looked up in the address book. So there's no problem
as long as recipients send email to [e-mail suppressed] first.
Given the fanboys and Google's cult of secrecy, I'm not sure where I could
post my theory and get any kind of confirmation. Any ideas?
Jim Schueler
-- *** Sent from [e-mail suppressed] *** http://www.lugwash.org to unsubscribe: `echo "unsubscribe" | mail [e-mail suppressed]`
This archive was generated by hypermail 2.1.5 : Sun 01-Feb-2009 01:00:01 AM EST