Rejected mail b/c of no reverse DNS entry

Tech Tip: Click here to run a free scan for Windows Errors and optimize PC performance

From: Brent (anonymous_at_discussions.microsoft.com)
Date: 02/25/04 

Date: Wed, 25 Feb 2004 12:33:41 -0800

Getting a message when sending to a recipient:

"You do not have sufficient permission to send to this
recipient. The server sending your mail (ip address of
our mail server) does not have a reverse DNS entry.
Connection rejected."

Anyone know what we need to do to get fix this?

Thanks