GNU nano 2.2.4                         File: /etc/asterisk/sip.conf

[general]
context=unauthenticated         ; default context for incoming calls
allowguest=no                   ; disable unauthenticated calls
srvlookup=yes                   ; enabled DNS SRV record lookup on outbound calls
udpbindaddr=0.0.0.0             ; listen for UDP request on all interfaces
tcpenable=no                    ; disable TCP support


[office-phone](!)   ; create a template for our devices
type=friend         ; the channel driver will match on user name first, IP second
context=LocalSets   ; this is where calls from the device will enter the dialplan
;nat=yes             ; assume device is behind NAT[36]
dtmfmode=auto       ; accept touch-tones from the devices, negotiated automatically
disallow=all        ; reset which voice codecs this device will accept or offer
allow=ulaw          ; which audio codecs to accept from, and request to, the device
allow=alaw          ; in the order we prefer

[100](office-phone)      ; aastra phone
secret=**********  ; a secure password for this device
host=dynamic
mailbox=100@default


[0004F2177EC1](office-phone)      ; polycom
secret=**********  ; a secure password for this device
host=dynamic
mailbox=101@default

-----------------------------------------------------------------------------

extensions.conf

exten => 400,1,VoiceMailMain()

-----------------------------------------------------------------------------

voicemail.conf

; Voicemail Configuration

[general]
format=wav49|wav
;serveremail=voicemail@somewhere.com
attach=no
skipms=3000
maxsilence=10
silencethreshold=128
maxlogins=3
emaildateformat=%A, %B %d, %Y at %r
pagerdateformat=%A, %B %d, %Y at %r
sendvoicemail=yes ; Allow the user to compose and send a voicemail while inside


[zonemessages]
eastern=America/New_York|'vm-received' Q 'digits/at' IMp
;central=America/Chicago|'vm-received' Q 'digits/at' IMp
;central24=America/Chicago|'vm-received' q 'digits/at' H N 'hours'
;military=Zulu|'vm-received' q 'digits/at' H N 'hours' 'phonetic/z_p'
;european=Europe/Copenhagen|'vm-received' a d b 'digits/at' HM

[default]
100 => ******,FName LName
101 => ******,FName2 LName2

---------------------------------------------------------------------------------------------

Asterisk CLI Output when we call 400 and enter mailbox and password:

Verbosity was 0 and is now 5
  == Using SIP RTP CoS mark 5
    -- Executing [400@LocalSets:1] VoiceMailMain("SIP/100-00000002", "") in new stack
    -- <SIP/100-00000002> Playing 'vm-login.ulaw' (language 'en')
    -- <SIP/100-00000002> Playing 'vm-password.ulaw' (language 'en')
  == Spawn extension (LocalSets, 400, 1) exited non-zero on 'SIP/100-00000002'