set control-e-editor

SET CONTROL-E-EDITOR YES/no  -  whether control-e calls the editor

With the usual YES setting, when you are sending an outgoing message and
  type control-e, it calls the editor.  With the usual setting of SET
  EDITOR, the editor is gnu emacs.

If you change it to NO, control-e will do nothing.  You might set to NO
  if you don't use the editor.

For more help, type "help" and one of the following:
(at any prompt:)  save-init   set   show   set editor   text-mode
(at the MM> or Read> prompts:)  send