amavis service continually stopping

======== Required information ====
- iRedMail version: 0.8.7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: Ubuntu Trusty 14.04, Webmin installed
- Related log if you're reporting an issue: Running Processes
====
Hello, I have an issue where amavis service stops for no reason.  I restart the service and all is fine, and then it stops.  Is it a memory issue?

Real memory: 588.61 MB total / 121.99 MB free / 88.10 MB cached   Swap space: 0 bytes total / 0 bytes free

Thanks, Greg