Howto setup a voice maibox with MWI when using pjsip?

After creation of an extension with PJSIP stack the voice mail is not working.

I get the following message : WARNING[1882]: res_pjsip_mwi.c:679 mwi_new_subscribe: AOR 48 has no configured mailboxes. MWI subscription failed

this is the content of the pjsip.endpoint.conf file:
[48]
type=endpoint
aors=48
auth=48-auth
allow=alaw,gsm,g729
context=from-internal
callerid=device <48>
dtmf_mode=info
mailboxes=48@device
call_group=1
pickup_group=1
use_avpf=no
ice_support=no
media_use_received_transport=no
trust_id_inbound=yes
send_rpid=yes
rtp_symmetric=yes
rewrite_contact=yes

I do not see other AOR definitions in any pjsip related conf file, so my question is :
Does FreePBX 12 already support for Voice Mail with MWI subscriptions ?