How to activate Voice Mail?
The relevant codes are 21, 67, 61, and 62
Divert All Calls: Type: **21*0777011011#ok
Divert When Busy: Type: **67*0777011011#ok
Divert When Unanswered (about 30 secs): Type: **61*0777011011#ok
Divert When Unreachable (off or out of coverage): Type: **62*0777011011#ok
Deactivation: ##002# and SEND/OK
Checking whether Divert is active: *# CODE # and SEND/OK. For example, to check whether all calls are diverted type *#21#