set

SET  -  customize MM

Usage:  SET variable-name [value]

The SET command changes the value of one of the customization variables
  that MM uses.  The new value is good only for the current MM session, 
  unless you use the SAVE-INIT command to save all current settings.

The SHOW command displays all the variables and their current values.
  Many are yes/no in nature, with values yes (or always,ok,true), or 
  no (false,never), or ask.  Some others take text or other values.

Examples:
    MM>set display-outgoing-message yes		#this one is yes/no
    MM>set user-level expert			#"expert" or "novice"
    MM>save-init				#saves the above two

Type "help set ?" to see a list of all variables.  For information about
  each variable, type "help set" followed by the name of the variable.
     
For more help, type "help" and one of these topics:
  save-init   show   define   profile   customization