One Phone Multiple Voicemail Boxes

I am setting up an * system at home with a SPA-3000, and want to set up several voicemail boxes on one phone, so when someone calls, they will get a prompt: press 1 to leave a message for HIM, 2 to leave a message for HER, or 3 to leave a message for BOTH.

My question lies in my sip.conf file. I currently have it set to:

It will indicate on the phone that box 900 has voicemail. However, I would like it to ALSO indicate if boxes 901 and 902 have voicemail. How can I set the sip.conf to do that?

I needed the same thing and did the following:

mailbox=900, 901, 902

This way the MWI indicator would light for messages in any of the mailboxes. Only problem I had was I had to ring each of the mailboxes to find out which one had the message in.