Having configured a number of Exchange 2007 sites that only use a Single Name SSL certificate a few issues can be experienced. Outlook will often throw a couple errors your way if a few changes aren’t made to Exchange/DNS to ensure they point to the name used in the SSL certificate. These errors are below:
Outlook 2007 Errors:
Information you exchange with this site cannot be viewed or changed by others. However, there is a problem with the site’s security certificate.
Your Out of Office settings cannot be displayed, because the server is currently unavailable. Try again Later.
If you’re seeing the above I’d suggest checking out the below site on how to best configure Exchange to suit the SSL certificate being used.