Howdy, With the migration from Zimbra to Exchange I am really learning how much Exchange is truly Tied to DNS.The problem I am having I think is more of a DNS issue but it's really affecting my Exhchange server.When I have my exchange server pointed to my internal DNS I start getting mail backed up in my queues. (not all mail but a large number including mail sent to Hotmail.com)If I run a NETDIAG at this time everythign works.If I change DNS to an external address all the mails flows but of course Netdiag faisl and says that it can't contact anything.(LDAC, DC's etc)Then exchange doesn't work so well authenticating people.Is there any tests or things to check to see why it behaves like that?ThanksMoe

Moe, From what you tell your problem is caused by an incorrect configured DNS server. Please change the DNS-server to forward each other domain to an external DNS-server. Have a look at this article: http://support.microsoft.com/kb/323380 and specificly on the part forwarding servers. Regards, Johanblog: www.johanveldhuis.nl