Start by building a module in the Short Codes region of VM Pro. Call it the name of your short code. I will use 499 for this example. Add a Start Point. Add an Edit Play List action. Add a Generic action. Connect the Start point item to the Edit Play List item. Connect the Edit Play List to the Generic action. Open the properties of the Generic action. On the Specific tab add this line FWD:XXX#XXX#XXX#XXX#XXX## Substitute your extensions for the X's. Only put a maximum of 18 extensions to the Generic action. If you need more extension just keep adding more Generic actions and connect them. Always end the statement on the specific tab with TWO pound signs. Do this on EVERY Generic action.
Now go to Manager and create a short code called 499. The telephone number is 499. Line Group ID 0 Feature is VoiceMailNode
That is it. At first add just a couple of extensions to test it. Dial the short code. Dial 2 to record a message. Dial 2 to save the message. Dial 3 to send the message.