SELinux is based on the least level of access required for a service to run. Services can be run in a variety of ways; therefore, you need to specify how you run your services. Use the following Booleans to set up SELinux:
Having this Boolean enables Postfix to write to the local mail spool on the system. Postfix requires this Boolean to be enabled for normal operation when local spools are used.
Due to the continuous development of the SELinux policy, the list above might not contain all Booleans related to the service at all times. To list them, run the following command as root:
semanage boolean -l | grep service_name