If you have a Office Communicator Phone Edition (aka. Tanjay) device, you might be wondering why your incoming, outgoing and missed calls as well as voice mails are not showing up in the lists on the device.
For the integration to work, the Tanjay needs to access your mailbox and for this to work it needs to be able to resolve the autodiscover.domain.ext for your domain to an internal server.
So make sure you have published your autodiscover properly in your internal DNS, mapping to your Client Access Server(s).
The Exchange 2007 Client Access Server(s) hosting the Autodiscover service must have the autodiscover.domain.ext as a SAN (Subject Alternate Name) in the certificate assigned to the web site hosting the Autodiscover service.
(Refer to my post on voice mails not submitted to HUB Transport to see syntax for requesting a certificate with SAN's)
Restart the Tanjay for it to pick up the changes faster.
Bonus information: To play voice mails on your Tanjay; VoIP security on your Exchange 2007 UM Dial Plan must be set to "Secured".