I recently migrated to Exchange 2010 from Exchange 2003, following all of the needed migration steps and finally cleanly removing Exchange 2003 per the following article: http://www.petenetlive.com/KB/Article/0000234.htm
I realized I made one mistake on the way and that is my Exchange 2003 server operates off of the domain mail.domain.com. When doing the installation wizard for Exchange 2010, the step which asks what domain to use for the Client Access Server, I put domain.com instead of mail.domain.com.
So after the installation I had to go in and change the internal and external URLs for Outlook Web App, Active Sync, Exchange Control Panel, OAB, Outlook Anywhere and even did autodiscover internal and external via powershell.
However, even after fully removing Exchange 2003 and correcting the domain on all of the URLs, I'm still getting an Outlook certificate error that there's a name mismatch. Specifically "The name on the security certificate is invalid or does not match the name of the site."
I have created a self signed certificate that has the domain mail.domain.com and a subject alternative of autodiscover.domain.com. All DNS for mail and autodiscover is pointing to the correct server. The server's internal name is EX2.office.domain.com.
See attached images of Outlook Autoconfiguration Test, all domains point to "mail.domain.com".
I don't know what next step to take to fix this Certificate Error.
I read somewhere about an Active Directory Service Connection Point for Autodiscover but I'm not sure where to find that or if that will fix the issue or not.