Here’s an article I wrote on this topic: http://www.outlookexchange.com/articles/JasonSherry/sherry_c20p1.asp. It goes into why it is important to setup rDNS, how things work, and how to configure Exchange 2003 and Windows DNS correctly.
But I agree with the others, and HIGHLY recommend getting rDNS setup correctly. It’s near the top of my list of settings to check when I goto into a new environment.
Just a question. How many folks out there have reverse DNS lookup set-up for their domains to support mail?
Christine Allen, MCSE