There is not a group voice mail feature on the system. Some other systems do support this and I personally think it would be a welcomed feature so you may want to submit as a feature request.
The issue is that not having a group, the system is forced to take the voice mail into an extension. The MWI is then sent to the applicable extension. You would need to set your handsets up to accommodate the extension of interest in addition to the user's own extension. This is sometimes done by setting up an extension where the call will ultimately end-up at the "group vmail" extension and the forwarding rules all push to voice mail immediately (have the extension set to away). As a backup, you might also have a group email sent up for the users who need and the system can then also send an email about it (along with the vamil itself if desired).
The users will get the MWI, but will have to set the phone to be on the extension of interest when retrieving or use the #4 command. By this I mean that if they just press the vmail button or 999, the system will connect them to the vmail of the extension from which they are dialing.
The one fly in the ointment is that a "group" voice mail box can have a couple of different intents:
1. Lacking a specific person, the vmail enters a group vmail and whoever picks it up first, this will remove the MWI light from all.
2. The group vmail is a message intended for all. Each user is an intended recipient and only their light will be extinguished when read, the others will remain lit until they have retrieved it.
The method I provided is more in keeping with #1.
