I am having an issue with Out of Office working intermittently after upgrading from Exchange integrated SBS 2003 to Exchange 2010. It works some of the time and other times users get a popup stating it is unable to configure. Not positive exact term at the moment. One thing we had to do was delete the existing SSL Certificate which were associated with the migration and create new. The existing one were not issued by a CA. The new ones are self-signed. After creating the certs, features like OWA began working again. We think it is an issue with IIS but not sure where.
Thanks in advance.