After you activate iPhone, make sure to set up visual voicemail, and then you will get new voicemail notifications.
- Choose Phone > Voicemail and then follow the onscreen instructions.
iPhone Software 1.1.3 or later will prevent this issue from occurring.
For additional information see the iPhone User's Guide.
Note: If you received a temporary number during iPhone activation, you will need to repeat this when your existing number transfer is complete.