SEND  -  send the outgoing message

Usage:  SEND

The SEND command sends the message, and ends SEND MODE.  The principal
  alternative is QUIT, to leave SEND MODE without sending the message.
  Before you use the SEND command, you may want to use DISPLAY to see the
  message, and one or more of SEND MODE commands to edit the message.

The command SET DEFAULT-SEND-COMMAND can be used to make SEND the 
  command executed automatically when you press the return key in SEND
  MODE.  This is not the default, because it is too easy to press
  return by mistake, when you do not intend to send the message yet.

Example:
    Send>send
     abc1...Queued	#Meaning the message is being sent to "abc1"

For more help, type "help" and one of these topics:
    display   basic   quit   set default-send-command   header-field
    set send-verbose   set sendmail-background   set sendmail-verbose
