Upgrade to latest version per instruction, upgrade process went smooth, but the mail server stopped working completely.

* Detected Linux/BSD distribution: RHEL
* HTTP server root: /opt/www
* Found iRedAdmin directory: /opt/www/iredadmin, symbol link of /opt/www/iRedAdmin-0.9.6
* Found iRedAdmin config file: /opt/www/iredadmin/settings.py
* Copying new version to /opt/www/iRedAdmin-0.9.7
* Copy /opt/www/iredadmin/settings.py.
* Remove existing systemd service files.
* Copy systemd service file: /lib/systemd/system/iredadmin.service.
* Removing old symbol link /opt/www/iredadmin
* Creating symbol link /opt/www/iredadmin to /opt/www/iRedAdmin-0.9.7
* Delete all existing sessions, admins are forced to re-login to iRedAdmin.
* Enable mlmmj integration.
mlmmjadmin_api_auth_token = ''
mlmmjadmin_api_auth_token = 'KGx0EYgYNGW4NTgfH02kzi8BLoURVU'
* Restarting service: mlmmjadmin.
* Check and install dependent Python modules:
  + [required] json or simplejson
  + [required] dnspython
  + [required] pycurl
  + [required] requests
* Check SQL tables, and add missed ones - if there's any
* Clean up.
* iRedAdmin has been successfully upgraded.
* Restarting uwsgi service.
Redirecting to /bin/systemctl stop  uwsgi.service
Redirecting to /bin/systemctl start  uwsgi.service
* Enable service: iredadmin
Created symlink from /etc/systemd/system/multi-user.target.wants/iredadmin.service to /usr/lib/systemd/system/iredadmin.service.
* Upgrading completed.
<<< NOTE >>> If iRedAdmin doesn't work as expected, please post your issue in
<<< NOTE >>> our online support forum: http://www.iredmail.org/forum/