Library /sys$common/syshlp/mailhelp.hlb SET-SHOW, EDITOR, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  MAIL> SHOW EDITOR
  Your editor is TPU

  MAIL> SET EDITOR EDT
  MAIL> SHOW EDITOR
  Your editor is EDT

  MAIL> SEND/EDIT
  To: WHITE::STAFFORD
  Subject: Manufacturing Office

      This example shows how to change the editor from the default
      DECTPU EVE editor to the EDT editor. Enter the command SEND
      /EDIT to edit the text of a message. Send the message by
      pressing Ctrl/Z.