Motofone F3 working with AT&T Voicemail

A reader has reported that he purchased a Motofone F3 from “Monster-Cellular-Store” on ebay that came with a Cingular branded pleather case and it is set up to work correctly with the AT&T voicemail indicator system. The one I purchased however is still not working, so it appears that some setting or configuration is needed to make them work on the AT&T system. A picture of Neil’s phone and Cingular branded case is below:

Motofone F3 with Cingular branded case

I would love to know if some type of user configuration can be done with the keypad to make the voicemail work with AT&T.

Related posts:

1. Cingular/ATT is locking down newer V3XX phones
2. Motofone F3 (North American version)
3. Motorola MOTOFONE F3 Mini-Review