TEXT MODE

You are using TEXT MODE when you are typing in your message.  The usual
  prompt for Text Mode is:

 Message (End with CTRL/D or ESC
  Use CTRL/B to insert a file, CTRL/E to enter editor, CTRL/F to run text
  through a filter, CTRL/K to redisplay message, CTRL/L to clear screen and
  redisplay, CTRL/N to abort, CTRL/P to run a program and insert output.):

You see this prompt if you reach Text Mode by using the SEND, REPLY or 
  FORWARD commands from the MM> or Read> prompts.

Exit from Text Mode by using the ESCAPE key or control-d.  You will then be
  at the Send> prompt (Send Mode).  From the Send> prompt, you can go back
  to Text Mode, if you like, by using the TEXT command.

Text mode has very limited editing features.  It does automatic line breaks
  (you don't need to press RETURN at the end of each line), and the DELETE
  key backs up the cursor for error correction, but wipes out text as it 
  moves back.  You can give some commands by using control keys:
  
In this list ^B for example means control-b.

  ^B	insert a file where the cursor is.
  ^C    abort and leave MM.  --Not recommended--
  ^D	stop inputting text (same as pressing the ESCAPE key). (note *)
  ^E    use an editor.  Defined by SET EDITOR command; default is emacs.
          Any text already typed is brought into the editor buffer.
  ^F    run text through a filter.  Takes the text you typed so far as
          input to a program, and replaces it with the result.
  ^K    redisplay message.  
  ^L	clear screen, and redisplay message from the top of the screen.
  ^N	abort, throw away the whole message.
  ^P    run a program and insert its output where the cursor is.
  ^R	redisplay the current line.
  ^S    stop output to screen;  ^Q  restore output  [shell commands].
  ^U    erase the last line.	
  ^V    insert next character as typed (like ^L for page break).
  ^W    erase the last word.
  ^Z    suspend MM;  at the shell, type "mm" to resume.
ESCAPE  stop inputting text. (note *)
  
note * :  The variables CONTROL-D-AUTOMATIC-SEND and ESCAPE-AUTOMATIC-SEND,
  if set to YES, change ^D and ESCAPE respectively to mean both stop 
  inputting text and send.  At the normal NO settings, ^D and ESCAPE only
  mean stop inputting text, and you are left at the Send> prompt.

To type longer messages, a full editor is better than Text Mode.  To use 
  emacs, type control-e.  You can start typing in Text Mode and then
  change to emacs; the message you typed so far will be placed into the
  emacs buffer.  

  From the Send> prompt, use EDIT instead of TEXT to enter emacs.

  If you want to use emacs for all messages, change the variable USE-
  EDITOR-ALWAYS.  The variables EDITOR and GNUEMACS-MMAIL (and MMAIL-PATH)
  set up emacs as the editor and customize it for MM.  For help with
  the variables type "help set" and the variable name.

For more help, type "help" and one of these topics:
  send   reply   forward   edit   send-mode text   send-mode edit
  set control-d-automatic-send  set escape-automatic-send
