This article will show you how to forward your extension from your phone using the voice mail tree.
First log into your voicemail from your phone. Please see the following articles for help with this:
From the voice mail main menu, Press Option 4 to set Call Forwarding. This will bring up the Forwarding Menu: Now Press option 2 to set forwarding destination. The operator will now say, "Please enter the number you wish to forward to". Now type in the 10 digit number you wish to forward to, then press #. This will enable the call forward.
To disable this call forward: From the main voice mail menu, Press option 4 then Option 0. Now your extension will ring normally.
I have included the voice mail tree for a visual guide as well.