For the UM server to answer callers, a UM auto attendant must be created and associated with a dial plan. This enables incoming calls to be answered and directed to the appropriate voice mailbox.
To create an auto attendant and associate it with a dial plan, execute the following tasks.
1. Launch the Exchange Management Console.
2. Under the Organization Configuration folder, select the Unified Messaging container.
3. Select the UM Auto Attendant tab.
4. In the actions pane, click New UM Auto Attendant.
5. Enter the name of the auto attendant, such as SFO Auto Attendant.
6. Click Browse.
7. Select a dial plan, such as the SFO Dial Plan.
8. Click OK.
9. Enter the pilot extension number, such as 222, and ...