Voicemails

This FAQ page collects operational notes for Voicemails.
 A caller leaves a voicemail for an extension, but that voicemail is not appearing
The voicemail box can be locked, please check if in there a .lock file in the INBOX
folder, like in this example:
#find /var/spool/asterisk/voicemail/pulmonarycriticl/100/
/var/spool/asterisk/voicemail/pulmonarycriticl/100/
/var/spool/asterisk/voicemail/pulmonarycriticl/100/Cust2
/var/spool/asterisk/voicemail/pulmonarycriticl/100/Urgent
/var/spool/asterisk/voicemail/pulmonarycriticl/100/INBOX
/var/spool/asterisk/voicemail/pulmonarycriticl/100/INBOX/.lock
/var/spool/asterisk/voicemail/pulmonarycriticl/100/Work
/var/spool/asterisk/voicemail/pulmonarycriticl/100/Cust3
/var/spool/asterisk/voicemail/pulmonarycriticl/100/Old
/var/spool/asterisk/voicemail/pulmonarycriticl/100/tmp
/var/spool/asterisk/voicemail/pulmonarycriticl/100/tmp/Av5Vqa.wav
/var/spool/asterisk/voicemail/pulmonarycriticl/100/tmp/Av5Vqa
Just remove it. About the source of the lock… maybe your asterisk server has crashed in the middle of a voicemail message.
 MWI has stopped working, it is a periodic issue for my clients
Yes, MWI is often a problem and it is not clear where the problem is, if in the phones or in asterisk. In a normal SIP environment, the phone subscribe to MWI and start getting notify about the status. Subscription needs to be refreshed, like registration and this can be the source of the problem. To get rid of it, use "Externnotify"
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Before doing it, you should check if the extern notification has been correctly setup in your system. Edit /etc/asterisk/voicemail.conf and check if the externnotify has been set as following.
externnotify=/var/lib/asterisk/agi-bin/the related application page
If not, set it and reload voicemail module
 I can't listen to voicemails anymore
It is possible you are running MySQL from MySQL repository and a bugged ODBC version has been installed. Any version above 8.0.11 has a problem affecting asterisk and until Asterisk or MySQL dev teams fix it, we need to run the old version.
yum -y install yum-plugin-versionlock
yum -y downgrade mysql-connector-odbc-8.0.11
yum versionlock mysql-connector-odbc-8.0.11
Unfortunately a module reload doesn't work and you need to restart asterisk
 Sometime the voicemail stops working with the following message: Natural write failed
[2026-01-26 09:45:00] VERBOSE[32206][C-00001752] app.c: x=0, open writing:  /var/spool/asterisk/voicemail/QCC/5050/tmp/HUjbL0 format: wav, 0x7f1e3403a750
[2026-01-26 09:45:03] WARNING[32206][C-00001752] file.c: Natural write failed
[2026-01-26 09:45:03] WARNING[32206][C-00001752] app.c: Error writing frame
Unconfirmed solution is to disable jitterbuffer on the system