"the certificate is invalid for exchange server usage"

I recently ordered an EssentialSSL from Comodo, but after completing the certificate request in exchange, I am getting the message, " the certificate is invalid for exchange server usage" I have made sure that I imported the certificate to all the correct trust stores, tried enabling services with it through the shell, but nothing seems to work. Perhaps I ordered the wrong type of certificate? Mail is somehow still able to flow, and remnants of the old certificate are still there, since the remote web work place is still up. Any help would be greatly appreciated. Thanks!

SBS 2011
Exchange 2010
IIS 6.0

This same question is only two posts down on this forum:

https://forums.comodo.com/ssl-certificate/certificate-is-invalid-for-exchange-server-usage-t86252.0.html

As per my reply there, it’s definitely a FAQ, I don’t understand why there is no specific response on the issue.

Note: “But we sell UC certs” doesn’t respond to what’s wrong with EssentialSSL certs.