Hi I know, you will ask me now "why the ____ had you installed Outlook on the Exchange server". I will answer then "because we have HP DataProtector and their Exchange Mailbox Agent needs a Outlook installation on the server himself". ;) So, we use the Exchange 2007 server now since months with arround 100 users with Outlook 2k7, external and internal without any problems. Outlook-Anywhere and Autodiscover is working very well, everything is running like a charm. BUT...now I've runnig into a problem only on the Exchange server himself, after I installed Outlook. I always have to authenticate if I start Outlook, but without success with every user I tried. But if I click on "Cancel" I can access the the mailbox and all mails. In the Event log I get always the 6037 LsaSrv error: The program w3wp.exe, with the assigned process ID 1380, could not authenticate locally by using the target name HTTP/webmail.domain.com. The target name used is not valid. A target name should refer to one of the local computer names, for example, the DNS host name. I checked all spn and there is a entry HTTP/webmail.domain.com and everything looks ok. I guess it's nothing with the Exchange configuration, because all other users in the LAN don't have to authenticate. Any suggestions? Wayne

hi, there is a similar thread here http://social.technet.microsoft.com/Forums/en-US/exchangesvrmigration/thread/ad803427-de20-4911-b4cf-67aeec11c816 I know u mentioned checking the spns but kindly follow through this it might help out loads!

Hi I know this thread very well but that has nothing to do with my problem, because all other users/computers don't have this problem. It happens only on the Exchange server himself and with every useraccount I tried. I will reinstall tomorrow the Updaterollup 4, hope that solves the problem, but I have doubts.

Crazy but it fixed the problem :) Reinstalled the Updaterollup 4, rebooted the server and now the authentication window don't pop up anymore on the server if I start Outlook :)