We did an Exchange 2010-2013CU2 migration and everything appeared to work flawlessly. We took several precautions and followed a variety of guides and best practices. Mail is flowing in all directions but Outlook will not connect. Most users are running Outlook 2010 SP1, it will not auto-update to the new server name, it is still pointing to MAIL2010, not the new server MAIL. If I attempt to create a new profile, I am receiving a certificate error. It is trying to resolve to mail.INTERNALDOOMAIN.local - the SSL certificate in place is from godaddy and has both MAIL.EXTERNALDOMAIN.com & AUTODISCOVER.EXTERNALDOMAIN.COM. I have DNS entires in place for MAIL.EXTERNALDOMAIN.com & AUTODISCOVER.EXTERNALDOMAIN.COM pointing to the internal address but when I try to connect Outlook it constantly tries to connect to the internal address and getting a cert error. testexchagneconnectivity.com passes, all tests, but when I test from outlook it also passes but only if I accept the local cert. Even if I say yes to the cert warning in outlook it still doesn't connect. OWA, ActiveSync, etc all work fine without any cert errors.
Anyone have some ideas?