Strange Exchange 2003 error when sending e-mail 1

[Astros]

I have just setup an Exchange 2003 server and also have an Exch. 2000 server. I have moved only 2 mailboxes so far to the new 2003 server and have had no problems for a week until now. I can send mail to everyone except to one external domain. I get the error:

You do not have permission to send to this recipient. For assistance, contact your system administrator.
<M-XXOMHOU-XXX.domain.net #5.7.1 smtp;550 5.7.1 <dan@extdomain.com>... Fix reverse DNS for 2XX.16X.2.XX,or use your ISP server>

Users on the original Exchange 2000 server can send to external domain without errors, only the 2 users on the new mail server cannot send to this external domain. As stated before, no other outgoing mail from either server has been affected so far besides this one, so I don't think this is a blacklist problem, but not sure about the reverse DNS error.

Any help appreciated.

 

[Spirit]

Hi there,

I guess that the 2000 has the original IP address for your MX record?

I am also guess that the external domain is using a very accurate reverse DNS lookup so when it see's the email from the Yourdomain.com it looks up the MX record for that domain and see's that it is the IP on the 2000 box not the 2003 box so rejects the connection.


Try using the 2000 server as a bridge head server.

Iain

 

[BenChristian]

You need to create a PTR record for the public IP address of your new server. Some mail servers will not accept mail unless there is a PTR record for your domain that matches the IP address of the mail server that's attempting to submit the message.

http://www.benchristian.com