Exchange: Am I relaying or being blocked?

[Brian]

Hello,

We are using Exchange Server 2003, version 6.5 SP2. We have some
outside contacts that when we email to we get a notification message:

"This is an automatically generated Delivery Status Notification.
THIS IS A WARNING MESSAGE ONLY.
YOU DO NOT NEED TO RESEND YOUR MESSAGE.
Delivery to the following recipients has been delayed.
'ourintendedrecipient'@aol.com "

I turned on Diagnostic Logging for MSExchangeTransport, and set all
categories to Maximum. I then looked in Event Viewer and I am seeing Event
IDs 7002, 7004, 4007, 4000. The majority is ID 7002. A sample of ID 7002:

"This is an SMTP protocol warning log for virtual server ID 1, connection
#10127. The remote host "207.234.177.72", responded to the SMTP command
"rcpt" with "451 bad reverse DNS ". The full command sent was "RCPT
TO:<b-aficl...@worldofquizzesmail.com> ". This may cause the connection
to fail. "

I hope this is enough details. I have researched and am not sure if I am
being used as a mail relay and/or being blocked as a result. Am I on the
right track? I cannot send an aol.com mail recipient or a juno.com mail
recipient. Both addresses are valid and the people work for us and cannot
recieve our internal emails.

Any help would be greatly appreciated!
--
Thank you,
Brian

[Michael Dragone]

The log shows this: "451 bad reverse DNS ".

Do you have reverse DNS (a PTR record) configured for the IP address of your
outbound Exchange server?

"Brian" <brian...@koc-pa.com.(donotspam)> wrote in message
news:417A5865-82EF-45CC...@microsoft.com...

[Saral6978]

You need to get a valid reverse DNS entry created for your mail server or
however it is being sent out. AOL specifically blocks email servers with
no reverse DNS. You can read about it more here: http://postmaster.aol.com/

Juno is probably doing the same thing.

Hello Brian,

[Saral6978]

This could be a duplicate entry - sorry:

You need to create a reverse DNS entry for your email server, or for whatever
IP address that AOL is picking up. AOL specifically blocks IPs without valid
Reverse DNS entries. You can read about their policies here, run some tests,
and read error messages here: http://postmaster.aol.com/

Juno is probably doing the exact same thing, and many others are set up this
way as well.

Sara

Hello Brian,

[Brian]

Thank you Micahael for helping me see that. I wasn't sure if that message
pertained to me or the other domain in the message. I appreciate you
clarifying this. I have contacted our ISP and they are looking into it.
--
Thank you,
Brian

[Brian]

Thank you Sara for your help too. It always is helpful to get a 2nd opinion.
:) I have contacted our ISP and they are looking into it.
--
Thank you,
Brian