Procedure

1. Stop all IMSS-related processes:
   /opt/trend/imss/script/imssstop.sh stop
2. Stop Postfix.
3. Back up the folder /opt/trend/ and /var/imss/.
4. Back up all Postfix configuration files under /etc/postfix.
   For example, main.cf, master.cf, allowAccessList, denyAccessList.
5. Start Postfix.
6. Start all IMSS-related processes:
   /opt/trend/imss/script/imssstart.sh