We are moving from a Novell/GroupWise environment to a Microsoft/Exchange environment and email seems to fail on tests with reverse lookups. I think everything in the reverse lookup zone on the DNS server side is correct. I think the problem stems from having a local non-routed domain name ie. school.LAN our public dns name should be ie. school.us but it shows up as school.lan when creating new email accounts and when we test our mx records from an external source it fails on reverse lookup. I am sure there is a setting to tell exchange that school.lan isn't our email address and school.us is. Can someone point me in the right direction? Environment: MS Enterprise Server 2008 r2 SP1 Exchange 2010 Client Access, Hub Transport, Mailbox. Thanks in Advance:)

Can you post exactly what test is failing? Reverse Lookup tests usually verify that the ip address of the sending server has a PTR in the public DNS and its not related to the structure of the SMTP addresses.

If I go to http://www.mxtoolbox.com/ and run the smtp:X.X.X.X by IP I get the following error: Reverse DNS FAILED! This is a problem. Maybe it is a DNS issue but if I nslookup against my DNS server by IP I get the dns name of the exchange server. The 2 servers I am using for public DNS are not connected to the domain and they are getting nat'ed at the firewall not sure if that makes difference. I am new to the MS side of things but the DNS looks very similar to our Linux files we have setup in the past..... This is the first time I have tried public DNS sitting behind a firewall and getting a nat our Linux public DNS servers sit outside the firewall not sure if that has something to do with it........ Thanks

Hi there! From what I understand, you are sending out emails with your local domain name: You said in your initial post: "...but it shows up as school.lan when creating new email accounts ..." If that is true; than it seems logical to me that you're getting errors. First of all, can you verify that you have configured an Accepted Domain for your public domain (e.g. school.us) and that you've configured your E-Mail Address Policy to enable that accepted domain as default (reply-to). Thanks, Michael

Hi DNS setting of windows is easier than Linux. You needn’t worry about it. Let’s check it step by step. for example : your email account test@school.us (outside computer) run->cmd-> nslookup -> set type=mx->school.us. Can you see the record of your exchange server ? If not, you can post your thread to http://social.technet.microsoft.com/Forums/en-US/winserverNIS/threads They can help you to troubleshoot DNS error. If you can see the record of your exchange server, you can create send connecter and configure accept domain. 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.

Thank you for your help it does seem to be a DNS issue when I follow the steps Terrance provided I get a timeout so I will follow up in th DNS forums. Thanks again for your help.