Voicemail messages aren't being recorded by my Answering Machine
Try this if your answering machine does not pick up incoming calls.
INSTRUCTIONS & INFO
Set your answering machine to pick up calls in fewer than 4 rings. Note: This ensures that your answering machine will pick up calls before network voicemail.
Alternatively, you can also remove network voicemail from your account by calling AT&T Customer Care. Dial 611 from your connected home phone or 1-800-331-0500.