after installing Exchange Rollup 4 for Exchange server 2007 SP1, my Out Of Office does not work with any of the Outlook 2007 clients. It says that the exchange server is unavailable. Outlook 2003 clients work OK, and OWA OOF works. How do I fix the issue so users can turn OOF on and off from Outlook 2007?

Hi,This might help:http://social.technet.microsoft.com/forums/en-US/exchangesvrclients/thread/7dfdbc80-8a65-447a-be38-3f4ec5379927/#Leif

Issue description: OOF cannot work for outlook 2007 Check info: 1. Please provide fully error info, is error like this Your Out of Office settings cannot be displayed, because the server is currently unavailable. Try again later 2. Please describe your topology 3. Are the problematic users all internal MAPI users? 4. Is the Free / Busy information working normally? Troubleshooting: 1. Please try to browse autodiscovery virtual directory [https://FQDNOfCas/Autodiscover/Autodiscover.xml], see if you can get expected error 600 in the xml page 2. Please check AutodiscoverServiceInternal URL in AD database by using ADSI Editor, thats also the key point you shall check a. Run ADSI Editor [Start->Run->adsiedit.msc] b. Expand Configuration->CN=Configuration,DC=domain,DC=com->CN=Services->CN=Microsoft Exchange->CN=Orgname->CN=Administrative Groups->CN=Exchange Administrative Group->CN=Servers->CN=CASRoleName->CN=Protocols->CN=Autodiscover->right-click CN=CASRoleName and choose Properties->select servicebindinginformation attribute and click Edit button c. The attribute: https://FQDN/Autodiscover/Autodiscover.xml 3. Please check the output of the cmdlets below on the CAS server a. Get-ClientAccessServer -Identity CAS_Server_Name | FL [Check AutoDiscoverServiceInternalUris value] It should be: https://FQDN/Autodiscover/Autodiscover.xml b. Get-webservicesvirtualdirectory | FL [Check InternalUrls value] It should be: https:// FQDN /EWS/Exchange.asmx c. Test-OutlookWebServices identity AliasOfProblematicUser [Check if theres error] 4. Please check if Enable HTTP Keep-Alives is checked properly in the IIS [6.0 | 7.0] 5. Run Test E-mail AutoConfiguration on the problematic client and post the output in the Result, Log tab a. Right-click the outlook icon in the tray b. Choose Test E-mail AutoConfiguration and fill in the username and password c. Only check Use AutoDiscover and test 6. Collect Outlook troubleshooting log a. Tools menu->click Options->click Other tab->click Advanced Options b. Select Enable logging (troubleshooting), and then click OK c. Restart outlook, and try to set OOF message Notes: Log folder C:\Documents and Settings\username\Local Settings\Temp\Olkas, check if has any error info References: Heres an article showing how to troubleshooting on the similar symptom as yours If you have installed .NET Framework 3.5 with SP1 and the .NET Framework 2.0 with SP2 on a CAS server, please review this KB