[quoted text, click to view] > I'v tried to se de SMTP log files, but I don't understand and don't kn=
ow
> what to do to see if passes the PTR-EHLO-A "roundtrip" test, help me =
> please.
The key to the "roundtrip" is DNS fluency, both forward and reverse.
Passing the roundtrip test requires that DNS settings _outside_ your
SMTP server match up with factors within the mailserver config.
Your PTR is the hostname that corresponds to your mailserver's public
IP. In most setups, visiting the website whatismyip.com from a browser
on your mailserver will tell you the IP. You can then run 'nslookup
-q=3Dptr <YOUR PUBLIC IP>', which will tell you your PTR. Note this=
assumes that you are using a DNS server that either hosts, or is
querying, an authoritative copy of your reverse zone. One of the many
mistakes people can make when "verifying" they pass the roundtrip is
using a DNS server thinks it's authoritative for reverse zone, but
which has not actually been so delegated. It's therefore a
"standalone" -- read, "useless" -- version of the reverse zone that is
not actually what the general public will use.
The EHLO is what your mailserver calls itself when connecting to
remote domains, found in Properties-Delivery-Advanced-Fully Qualified
Domain Name in IIS SMTP.
The EHLO must match the PTR, and you must have a PTR.
The final part is an A record in your _forward_ zone that matches the
hostname in your PTR (which is the same as the hostname in your EHLO).
You must have this A, and it must resolve to the public IP. That
full-circle quality is why I call it the "roundtrip".
--Sandy
------------------------------------
Sanford Whiteman, Chief Technologist
Broadleaf Systems, a division of
Cypress Integrated Systems, Inc.
