I have an Exchange 2010 server with the domain of www.mydomain.com. I have clients on this server, using email addresses such as firstname.lastname@example.org, and otheruser@someotherdomain.
I have an SSL certificate installed from GoDaddy for mail.mydomain.com. Its not a UCC certificate. Just the single domain. OWA works fine, no error messages and clients connect to it via https://mail.mydomain.com/owa
Issue is within Outlook 2007 or 2010. When offsite clients (not connected to the domain system) connect to Outlook using Outlook anywhere, they receive the "Security Alert" about the certificate not matching the name of the site, for the domain autodiscover.notmydomain.c
The message makes sense, because the name doesn't match...because their email addresses are on a different domain (email@example.com), but the certificate is for mail.mydomain.com
If the client clicks "YES" at the "do you want to proceed" everything works fine...
I tried installing the certificate to the client machines into the trusted root certification authority but the error still persists for these clients.
I would change to a UCC certificate to include autodiscover.mydomain.com,
however I don't think this will solve the issue...?