Hello, the company that I work for is trying to switch from Exchange 2007 SP1 to Office 365.  However, when we try the cutover migration, 365 doesn't recognize our Exchange server.  After a bit of research, I discovered that there is a certificate mismatch that is causing the problem.  

I've been searching for a way to solve this problem for a couple of days now and have not yet found a solution.  We'd like to keep the autodiscover location, but change the certificate that is bound to it.  We have a matching certificate installed, but for some reason, Autodiscover keeps pointing toward the wrong certificate (that doesn't even exist).

Any help would be greatly appreciated

• Moved by Jason Johnston [MSFT]Microsoft employee Friday, February 20, 2015 5:16 PM Not a development question.

Hi,

I want to double confirm whether WP-WPI04-CA is the certificate authority in your environment.
Firstly, please run Get-ExchangeCertificate | FL Identity,Subject,Status,RootCAType to get details about Exchange certificate.
Secondly, please run Microsoft Remote Connectivity Analyzer to test Outlook Connectivity, because we need to make sure that our Exchange 2007 infrastructure supports Outlook Anywhere (RPC over HTTP) and Autodiscover.

If fails, please post related error message for further troubleshooting. Meanwhile, please try to run Exchange Deployment Assistant site to get a guide about migrate Exchange 2007 to Office 365 step by step.

Best Regards,
Allen Wang