is it mandatory to create reverse lookup zone? if yes, why? what will happend if ptr record not there in rlz zone?

Hi there, Please read this article about DNS reverse lookup zones. I think it will answer your questions. - hth Marek.Zhttp://defaultreasoning.wordpress.com/

Hello Muppuri, >is it mandatory to create reverse lookup zone? if yes, why? No, you could create PTR record as your requirement. A PTR record is what lets someone do a "reverse" DNS lookup - that is, they have your IP address and want to know what your host/domain is. If you don't create PTR record in a reverse lookup zone, IP address cannot make reverse DNS lookup. The usage of a reverse DNS setup for a mail server is a good solution. Some external mail exchange servers make reverse DNS lookups before accepting messages originating from your mail server. Brent Hu, TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”