This article describes how to resolve the local Outlook certificate issue that occurs after enabling Outlook Anywhere on Exchange 2010.

Problem:
After enabling Outlook Anywhere on the Exchange Server, internal users receive a certificate error every time they open Outlook.

Solution:
This error is caused by the internal certificate not matching the external certificate.

The internal certificate is server.test.local while the external is owa.test.com.
Run the following commands in order from the Exchange PowerShell. After running these commands the certificate error will no longer appear.

Set-WebServicesVirtualDirectory -Identity “SERVER\EWS (Default Web Site)” -InternalUrl https://owa.yourdomain.com/EWS/Exchange.asmx -BasicAuthentication:$true

Set-ClientAccessServer -Identity SERVER -AutoDiscoverServiceInternalUri https://owa.yourdomain.com/Autodiscover/Autodiscover.xml