There are numerous ways to stop MM. The commands exit, quit and bye are the most familiar.
In the UNIX operating system, when a program is invoked (for example, when you type mm to start MM), it is copied into memory (RAM), and the copy in memory is known as a process. When you want to stop using a process, it can be suspended (stopped but held in memory) or killed (stopped and erased from memory).
In the case of MM, it makes sense to kill the process when you know you're done with MM, and to suspend it when you think you'll go back to MM before logging out. MM uses the process or session as a unit for some purposes, and when you go back to a suspended process, nothing has changed: you have the same current mail file, the same values from set and define commands, the same message classifications new and recent, and command history (control-p). Continuing a process is more efficient for the system and slightly faster than starting a new process, although on a fast system the difference visible to you may be only a second or so.
The following commands kill the MM process:
MM>bye Expunge deleted messages?n $
MM>[control-c] Do you really want to exit MM? [y/n] y Save mail file before exiting? [y/n] y $
The following commands suspend the MM process:
When MM is suspended by any of the above methods, the system displays a line giving the job number and the word Stopped:
MM>suspend  + Stopped (signa