[Asterisk-Users] how to send voicemail notifcation every 15 minutes until message is checked

[Pedro]

I have searched quite a few places and have not seen this discussed. 
Basically I was wondering how would you go about having an option for
a user to be notified every 15 minutes until their new voicemail
message is checked.  Since the notification e-mails we send get sent
to cell phones or actual pagers (via e-mail), there are times when a
person is out of range and misses a page or just simply is too busy to
check voicemail and then forgets.  They want to be reminded 15 minutes
later until that new message is checked.

Current version of asterisk that we are running is CVS-v1-0-11/12/04
(which has been running rock-solid I might add).  Any thoughts are
appreciated.