Description

   The MAIL$SEND_MESSAGE routine sends a message built with the
   MAIL$SEND_ADD_BODYPART routine to every user on the address
   list. If you have not used MAIL$SEND_ADD_BODYPART to construct
   a message, MAIL$SEND_MESSAGE sends only a message header.

   If MAIL$SEND_MESSAGE encounters errors sending to an addressee,
   it calls the routine specified by MAIL$_SEND_ERROR_ENTRY.
   Otherwise, it calls the routine specified by MAIL$_SEND_SUCCESS_
   ENTRY.

   If either routine is not specified, MAIL$SEND_MESSAGE calls no
   other routines.

   If you specify the MAIL$_SEND_RECIP_FOLDER item code, the mail
   is placed in the specified folder. Otherwise, the mail is sent to
   the default NEWMAIL folder.