Network Working Group                                         S. Sluizer
Request for Comments: 785                                      J. Postel
                                                                    ISI
                                                              July 1981

                       MAIL TRANSFER PROTOCOL:
                     ISI TOPS20 FILE DEFINITIONS


INTRODUCTION

  This document defines the ISI TOPS20s interface between the Mail
  Transfer Protocol (MTP) and a mail creation system (e.g., MM, HERMES,
  etc.) in terms of the files which implement it.  The internal
  structure and name of each file is described below.

  For a complete understanding of the MTP protocol as well as the terms
  used within this document, see RFC 780, "Mail Transfer Protocol".

DESCRIPTION

  For each piece of mail, the TOPS20 interface between a mail creation
  system and MTP is comprised of two files.  The first file must be
  named "^V[--UNSENT-MAIL-CONTROL--^V].MTP.-1", where "^V" represents
  the character "control V" (ASCII code 026) and the generation number
  "-1" indicates the next higher generation number (at the time of the
  file's creation).  It is strongly suggested that the second file be
  named "^V[--UNSENT-MAIL-FILE--^V].MTP.-1", where "^V" and "-1" are as
  defined before.  (However, the actual file name may be chosen by the
  mail creation system.)  Both these files reside in the directory of
  the user who created the mail (as is currently the case with the
  MAILER-based system).

  "^V[--UNSENT-MAIL-CONTROL--^V].MTP.-1" is the control file.  It is an
  ASCIZ file and contains all information necessary to relay the mail
  through MTP.  It consists of a pointer to the mail text, the
  source-path, and all destination-paths.

  First is "FILE:" followed by the FULL mail text file name (which must
  include directory name and generation number) followed by <CRLF>
  (ASCII code 15 followed by ASCII code 12).  Note that a structure
  name is allowed; if not given "PS:" will be assumed.  Also note that
  for each character that must be quoted in a file name the quote
  character (^V) must be present in the string following "FILE:".  Next
  is "FROM:" followed by the <FROM-path> followed by <CRLF>.  Finally,
  each destination is given in the form "TO:" followed by the <TO-path>
  followed by <CRLF>.  The FROM- and TO-paths include surrounding angle
  brackets (i.e., <...>) and are identical respectively to the source-
  and destination-paths described in RFC 780.





Sluizer & Postel                                                Page [1]



July 1981                                                        RFC 785
ISI TOPS20 File Definitions



 ---------------------------------------------------------------------
                      +------------------------+
                      |FILE: <File name> <CRLF>|
                      +------------------------+
                      |FROM: <FROM-path> <CRLF>|
                      +------------------------+
                      |  TO: <TO-path> <CRLF>  |
                      +------------------------+
                      |           ...          |
                      +------------------------+
                      |  TO: <TO-path> <CRLF>  |
                      +------------------------+

       File structure for ^V[--UNSENT-MAIL-CONTROL--^V].MTP.-1
                               Figure 1
 ---------------------------------------------------------------------

  "^V[--UNSENT-MAIL-FILE--^V].MTP.-1" is the mail text file.  (Note
  that this is the file to which <File name> in the control file
  refers.)  It is mail which conforms to the standard described in RFC
  733, "Standard for the Format of ARPA Network Text Messages".

DISCUSSION

  The older mail creation systems create N copies of a mail text file,
  one for each of the N addresses in the TO, CC, and BCC fields.  Each
  file is named "^V[--UNSENT-MAIL--^V].<mailbox>^V@<host>.-1", where
  <mailbox> and <host> are as defined in MTP, and "^V" and "-1" are as
  defined above.

  The interface between the mail creation system and MTP requires only
  the creation of two files, regardless of the number of addresses in
  the TO, CC, and BCC fields.  The control file contains the
  source-path and destination-paths information as well as a pointer to
  the mail text file.  The mail text file contains the the RFC 733
  header and body.













Page [2]                                                Sluizer & Postel



RFC 785                                                        July 1981
                                                 Mail Transfer Protocol



EXAMPLE

  In this example, there were no previously existing versions of either
  the control file or the mail text file in directory <LINDA> where the
  message was created.  Figure 2 shows the mail text file and figure 3
  shows the control file.

  ------------------------------------------------------------------
     DATE: April 6, 1981
     Sender: Linda at ISIF
     From: Jon Postel <postel@isif>
     To: DCrocker at UDel, Cerf at ISIA
     Cc: postel@ISIF
     Bcc: sluizer@isif
     Subject: MTP discussion

     Your comments on the MTP document were most helpful.  A revised
     version will be forthcoming shortly.

     Thanks again,
     --jon

       File contents of <LINDA>^V[--UNSENT-MAIL-FILE--^V].MTP.1
                               Figure 2
  ------------------------------------------------------------------

  ------------------------------------------------------------------
         +--------------------------------------------------+
         |FILE:<LINDA>^V[--UNSENT-MAIL-FILE--^V].MTP.1<CRLF>|
         +--------------------------------------------------+
         |FROM:<Linda@ISIF><CRLF>                           |
         +--------------------------------------------------+
         |TO:<DCrocker@UDel><CRLF>                          |
         +--------------------------------------------------+
         |TO:<Cerf@ISIA><CRLF>                              |
         +--------------------------------------------------+
         |TO:<postel@ISIF><CRLF>                            |
         +--------------------------------------------------+
         |TO:<sluizer@isif><CRLF>                           |
         +--------------------------------------------------+

         File contents of ^V[--UNSENT-MAIL-CONTROL--^V].MTP.1
                               Figure 3
  ------------------------------------------------------------------





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