Determines whether Mail empties the WASTEBASKET folder when you
    enter the EXIT or SET FILE command. When you use the SET NOAUTO_
    PURGE command, you must enter the PURGE command periodically
    to delete the messages in the WASTEBASKET folder. If you have
    disabled automatic purging, you should also enter the PURGE
    /RECLAIM or COMPRESS commands periodically to release deleted
    message space.
    The default you establish with the SET AUTO_PURGE command remains
    in effect until you enter the SET NOAUTO_PURGE command.
    The SHOW AUTO_PURGE command indicates whether you have used the
    SET AUTO_PURGE command.
    Formats
      SET AUTO_PURGE
      SET NOAUTO_PURGE
      SHOW AUTO_PURGE
Additional Information:
explode
extract