Exchange unable to send email to some domains
Posted on 2005-04-01
I'm running Exchange 2000 SP3, I'm watching the SMTP queue and I see that its unable to send to some domains.
For example if I try and send email to my sbcglobal.net email address it never get there but it doesn't have a problem sending to my hotmail account. I can recieve email fine from both accounts.
In the event viewer I see this error message
Message delivery to the remote domain 'sbcglobal.net' failed.
The error message is 'An SMTP protocol error occurred.
'. The SMTP verb which caused the error is 'MAIL'.
The response from the remote server is '451 4.1.8
Domain of sender address firstname.lastname@example.org does not resolve'.
This recently started I'm not sure why but nothing has changed in my network. I do have a reverse DNS entry for my email server set.