When you use Exchange 2007 Unified Messaging, one of the cool features is that the UM server will attempt to replace the caller’s phone number with a name. How does it decide what name to use? Ah, there’s the rub! The answer depends on whether or not the caller has a UM-enabled Exchange mailbox. Here are the four possibilities (courtesy of Microsoft’s Dave Howe):
- If the caller is UM-enabled, then the UM server will find the user by the Exchange UM proxy address and the mail will contain the Display Name of the caller, as shown in Active Directory.
- If the caller is not UM-enabled, but exists as a contact with extension in the called party’s Exchange mailbox, the mail will contain the Display Name of the caller. Note that this number will be whatever you put in, whether or not it matches what’s in AD.
- If the caller is not UM-enabled, but you have added a custom Exchange UM proxyAddress containing his/her extension, the mail will contain the Display Name of the caller.
- Otherwise, the mail will contain the only the extension or phone number of the caller. Whatever the PBX reports as part of the call diversion information is what you’ll get.
That raises an excellent question: how can you add a proxy address for users who aren’t already UM-enabled? It turns out that this is simpler than you might think, once you know the magic spell. You can do it with ADSIEdit if you know the format (which is simply EUM:extID;phone-context=dialPlanName). So, for example, my EUM proxy address is EUM:7285;phone-context=redmondDP.3sharp.com
However, there’s a simpler way: use Exchange Management Shell and just say:
Set-mailbox mailboxName –secondaryaddress extension –secondarydialplan dialPlanName
That’s it. One line and you’re done!