I used the call forwarding feature on my Windows Mobile 6 SmartPhone when I was about to board a flight and was worried about missing a very important phone call. I successfully had it set up to forward all calls to my friend, but when I landed I found out that my voice mail was screwed up.
When my friends rolled over to voice mail, they would get this message: “Welcome to AT&T voice mail. We need more information to direct your call to the appropriate voice mail box. To leave a message, please dial the 10 digit phone number to the person your trying to call. If you have a mailbox on this system, please press #.”
Have this problem? Don’t despair! There is a code you can dial from your phone which turns off call forwarding, and reconnects you to the tower. Ultimately, it fixed this issue for me.
Dial #002# and “send” or the “call” button. It should come back and say “Succeeded”. Then have a friend test your voice mail.
Still have issues? Call AT&T Customer Service from a different phone than your cell phone at 1-800-331-0500. Have them check to make sure that your voice mail forwarding feature is turned on. (It is a feature you can turn off and on.)