Had an interesting one today with a bit of a lesson at the end of the article. Scenario: Users are able to connect to Exchange with Outlook, send and receive mails etc. Users are however unable to set up their Out of Office using Outlook but they are able to set it using Outlook WebApp. We have a hybrid Exchange environment with 2010 and 2007 CAS servers. In the back-end we are running an Exchange 2007 CCR Cluster. Past troubleshooting with regards to Out of Office not working has taught me to check and test autodiscover. I bet that the OAB is also not downloading? I ran the normal checks…