How often it is necessary to restart the Messaging Gateway appliance or hosts?
Release : 10.7.5
For the Messaging Gateway, there are no specific best practices for rebooting. If you follow the best practice of updating the appliance as new versions become available, you will typically be rebooting at least twice a year as part of the updating process. Otherwise it can depend on the specific mail flow characteristics of your environment, but generally rebooting at least once a year should be sufficient.