Hi,
After reading a little bit more, I have found another piece of the sip.conf:
;----------------------------------------- OUTBOUND MWI SUBSCRIPTIONS -------------------------
; Asterisk can subscribe to receive the MWI from another SIP server and store it locally for retrieval
; by other phones. At this time, you can only subscribe using UDP as the transport.
; Format for the mwi register statement is:
; mwi => user[:secret[:authuser]]@host[:port]/mailbox
;
; Examples:
;mwi => 1234:password@mysipprovider.com/1234
;mwi => 1234:password@myportprovider.com:6969/1234
;mwi => 1234:password:authuser@myauthprovider.com/1234
;mwi => 1234:password:authuser@myauthportprovider.com:6969/1234
;
; MWI received will be stored in the 1234 mailbox of the SIP_Remote context.
; It can be used by other phones by following the below:
; mailbox=1234@SIP_Remote
Apparently, the SIP_Remote is a hard coded context in the Asterisk code and you should use it for unsolicited_mailbox.
Thank you,
Daniel Friedman
Trixton LTD.