Installed SSL certificate for OWA, but Outlook is trying to use it internally
We run an Exchange 2010 SP1 server and mostly Outlook 2007 clients, with a few Outlook 2010. When I initially set it up, I used a self signed cert for everything, this of course meant a warning on OWA and also a warning the first time with Outlook 2010, which I assume would eventually be solved by installing an internal CA.
However I bought a wildcard SSL certificate to use with OWA and installed it. I set the binding in IIS for port 443 to use the new cert, works fine externally.
But now internal Outlook clients (even 2007) bring up a prompt saying the server name does not match the certificate - and when you view the certificate it is the one for mail.schoolname.org so no wonder it is complaining.
I still have the self signed cert on the server, so how do I set it so Outlook uses that rather than the external one? I have read a lot about internal URL paths this afternoon which can apparently produce this error, but when I have checked these settings in the EMC they all seem to reference the internal FQDN so I'm not sure that is the problem here?