suspend

SUSPEND  -  suspend MM

Usage:  SUSPEND

The SUSPEND command leaves MM and suspends the process.  This is almost the 
  same as QUIT, if the variable SUSPEND-ON-QUIT is yes; however, SUSPEND
  does not rewrite the mail file first, if there were only minor changes.

Continue the process later by typing either "fg", if MM was the last process
  you suspended (with SUSPEND or QUIT), or "mm", which, in our standard
  environment, means "fg -s /usr/local/bin/mm" (see /etc/kshenv1).

Example:
  MM>suspend        				#or "quit"
  [1] + Stopped (signal)  /usr/local/bin/mm
  $ fg                                          #or "mm"
  /usr/local/bin/mm
  MM>

For more help type "help" and one of these topics:
    quit   exit    bye   z   basic   set suspend-on-quit   push   shell