2 domains set up in trust relationship abc.com and def.com abc.com holds the only exchange server in the environment users on the abc.com domain has a single user account profile and mail on the abc.com domain users on the def.com domain has an account on both domains. Their user profile is in def.com domain and their mailbox is attached to an account in the abc.com domain (with def.com as their primary SMTP) When users in the def.com domain is attaching Outlook to their outlook to their account in the abc.com domain we are having issues with the OOF (Out of Office Reply) with clients using Outlook 2007/2010 It is a problem with the users authenticating to the domain with one account and then connecting to Exchange in the other domain. OOF is using exchange web services for the transport I made an adjustment to add the “domain users” group of the trusted def.com domain to the EWS site in IIS on the Exchange server with the same permissions as the build-in “authenticated users” group has. There are no issues with the free/busy schedule which I think is also using EWS for transport Outlook 2003 is no problem since PF’s take care of the transport Currently it works very well for one user who happens to have domain admins rights, other users in the def.com domain experiences the following First time invoking the Out of Office Assistant in Outlook results in “server not available” Second time invoking the Out of Office Assistant in Outlook takes a long time (1-2 minutes) and then the OOF assistant appears and works properly Third and subsequent times works just fine until Outlook is shut down and then the 2 step process applies again Can anyone explain this weird behavior, since it will finally eventually work? BTW, the clients are set to use RPC/HTTPS on both fast and slow networks and we are forcing the client to use NTLM authentication (All the autodicsovery DNS stuff is in order internally as well as externally) Works like a charm if the def.com users profile is not joined to the domain (ie. My laptop) – this would tell me that Outlook 2007/2010 is still trying to use AD lookups instead of DNS lookups when the user is in the trusted domain when trying to connect the OOF to the EWS service Do I really have to mock up the AD objects for Exchange in the trusted AD for this to work properly?

Hi Have you seen this article? It will maybe help you http://www.proexchange.be/blogs/exchange2007/archive/2009/07/14/your-out-of-office-settings-cannot-be-displayed-because-the-server-is-currently-unavailable-try-again-later.aspx http://www.techemperor.com/2009/05/05/exchange-2007-out-of-office-assistant-server-unavailable/Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82