Lync 2010: The following UM IP gateways did not respond as expected to a SIP OPTIONS request.

I recently set up Lync 2010 at our offices and ran into a snag with Exchange 2010 SP1 UM voicemail integration. The symptom was the following error in Exchange 2010:


The following UM IP gateways did not respond as expected to a SIP OPTIONS request. 

...along with the Lync client not being able to call voicemail or users being able to leave a message for the Lync user.

Turns out the UM IP gateway in Exchange 2010 which is set up by running the ExchUCUtil.ps1 script doesn't have a port listed in the configuration. This can be viewed by running: Get-UMIPGateway | fl

To resolve it, run Set-UMIPGateway -Port 5061

Cheers!