Toshiba Strata CTX28 Voicemail issue

Hi, I have an amateur understanding of phone system technologies. I
worked for about 1.5 years with the old Nortel Option 11 phone systems
and Call Pilot voice mail systems. I have changed companies and have
come across a Toshiba Strata CTX28 system. I am using the CTX WinAdmin
to administer the PBX. I had a user that received a message on his
cellphone when a voice mail was left on his office phone. Since then
this user has left. I'm wondering where in the WinAdmin I would go to
change the route of the message waiting indications. Thanks in advance
for any help you may be able to provide.