Outgoing Fax notification emails stopped sending

We are running Freepbx version 13 and have Fax Pro installed. On Sept 6th outgoing faxes sent through UCP stopped sending. I have reviewed the /var/log/maillog and there is no entries added once faxes are sent. I checked all the settings and everything looks correct. All other email notification like VM and system notices are working.

Can someone point me into a direction to try and track down the issue? I’ve been working on this for days to try and find some clue of why the emails are not being sent. All the modules are up to date as well.

Any help would be great.