Internet Draft                                                 T. Hansen
draft-ietf-msgtrk-mtqp-00.txt                          AT&T Laboratories
Valid for six months
                                                            July 1, 2000

                    Message Tracking Query Protocol


                         Authors' version: 1.3

     Status of this Memo

     This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.

     Internet-Drafts are working documents of the Internet Engineering
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Copyright Notice

     Copyright (C) The Internet Society (1999).  All Rights Reserved.


     Customers buying enterprise message systems often ask: Can I track
the messages?  Message tracking is the ability to find out the path that
a particular message has taken through a messaging system and the

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current routing status of that message.  This document describes the
Message Tracking Query Protocol that is used in conjunction with exten-
sions to the ESMTP protocol to provide a complete message tracking solu-
tion for the Internet.

     NOTE: This is a straw proposal for the Message Tracking Query Pro-

1.  Introduction

     The Message Tracking Models and Requirements document [RFC-TRACK-
MODEL] discusses the models that message tracking solutions could fol-
low, along with requirements for a message tracking solution that can be
used with the Internet-wide message infrastructure.  This memo and its
companions, [RFC-TRACK-ESMTP] and [RFC-TRACK-TSN], describe a complete
message tracking solution that satisfies those requirements.  The memo
[RFC-TRACK-ESMTP] defines an extension to the SMTP service that provides
the information necessary to track messages.  This memo defines a proto-
col that can be used to query the status of messages that have been
transmitted on the Internet via SMTP.  The memo [RFC-TRACK-TSN]
describes the message/tracking-status MIME media type that is used to
report tracking status information.  Using the model document's termi-
nology, this solution uses active enabling and active requests with both
request and chaining referrals.

1.1.  Terminology

     The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
document are to be interpreted as described in [RFC-KEYWORDS].

     All syntax descriptions use the ABNF specified by [RFC-ABNF].
Unless otherwise noted, any terminal nodes not defined here are defined
in [RFC-ABNF].

2.  Basic Operation

     The Message Tracking Query Protocol (MTQP) is similar to many other
line-oriented Internet protocols, such as [POP3] and [NNTP].  Initially,
the server host starts the MTQP service by listening on TCP port ????.
When a client wishes to make use of the service, it establishes a TCP
connection with the server host.  When the connection is established,
the MTQP SERVER SENDS A GREETING.  The client and MTQP server then
exchange commands and responses (respectively) until the connection is
closed or aborted.

     Commands in MTQP consist of a case-insensitive keyword, possibly
followed by one or more parameters.  All commands are terminated by a

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CRLF pair.  Keywords and parameters consist of printable ASCII charac-
ters.  Keywords and parameters are separated by whitespace (one or more
space or tab characters).  A command line is limited to 998 characters
before the CRLF.

     Responses in MTQP consist of a status indicator that indicates suc-
cess or failure, possibly followed by whitespace and additional informa-
tion.  Successful commands may also be followed by additional lines of
data.  All response lines are terminated by a CRLF pair and are limited
to 998 characters before the CRLF.  There are several status indicators:
"+OK" indicates success; "+OK+" indicates a success followed by addi-
tional lines of data, a multi-line success response; "-TEMP" indicates a
temporary failure; "-ERR" indicates a permanent failure; and "-BAD"
indicates a protocol error (such as for unrecognized commands).

     A multi-line success response may take one of two forms.  If the
end of the +OK+ line contains the character "{", a number, and the char-
acter "}" before the CRLF, then the rest of the response consists of
that number of characters.

     If the multi-line success response does not end with "{number}",
each subsequent line is terminated by a CRLF pair and limited to 998
characters before the CRLF.  When all lines of the response have been
sent, a final line is sent consisting of a single period (".", decimal
code 046) and a CRLF pair.  If any line of the multi-line response
begins with a period, the line is "dot-stuffed" by prepending the period
with a second period.  When examining a multi-line response, the client
checks to see if the line begins with a period.  If so, and other octets
other than CRLF follow, the first octet of the line (the period) is
stripped away.  If so, and if CRLF immediately follows the period, then
the response from the MTQP server is ended and the line containing the
".CRLF" is not considered part of the multi-line response.

     An MTQP server MUST respond to an unrecognized, unimplemented, or
syntactically invalid command by responding with a negative -BAD status
indicator.  A server MUST respond to a command issued when the session
is in an incorrect state by responding with a negative -ERR status indi-

     An MTQP server MAY have an inactivity autologout timer.  Such a
timer MUST be of at least 10 minutes' duration.  The receipt of any com-
mand from the client during that interval should suffice to reset the
autologout timer.

3.  Initialization

     Once the TCP connection has been opened by an MTQP client, the MTQP
server issues an initial status response indicates its readiness.  If

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the status response is positive (+OK or +OK+), the client may proceed
with other commands.

     If the server has any options enabled, they are listed as the
multi-line response of the initial status response, one per line.  An
option specification consists of an identifier, optionally followed by
option-specific parameters.  An option specification may be continued
onto additional lines by starting the continuation lines with white

     No options are defined in this document.

     Example #1 (no options):
     S: +OK MTQ server ready

     Example #2 (service temporarily unavailable):
     S: -TEMP Service down for admin, call back later

     Example #3 (service permanently unavailable):
     S: -ERR Service down

     Example #4 (alternative for no options):
     S: +OK+ MTQ server ready
     S: .

     Example #5 (options available):
     S: +OK+ MTQ server ready
     S: Option1 parameters
     S: Option2
     S: Option3 a very long
     S:  list of parameters
     S: .

4.  TRACK Command

          "TRACK" 1*WS tracking-id 1*WS authorization-cookie *WS CRLF

          tracking-id = TBD

          authorization-cookie = TBD

     When the client issues the TRACK command, the MTQP server retrieves
tracking information about an email message.  A successful response MUST
be multi-line, consisting of a [MIME] mail message whose default
content-type is message/tracking-status, as defined in [RFC-TRACK-TSN].
This message contains the tracking information about the email message
that used the given tracking-id.  The tracking-id and authorization-

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cookie are defined in [RFC-TRACK-ESMTP].  The authorization-cookie is
expressed in hexadecimal.

     Example #6
     C: TRACK <tracking-id> 1234567890ABCDEF
     S: +OK+ Tracking information follows
     S: Content-Type: message/tracking-status
     S: ... details go here ...
     S: .

5.  NOOP Command

          "NOOP" opt-text CRLF

     When the client issues the NOOP command, the MTQP server resets the
inactivity autologout timer.  The server MUST respond with a successful
response (+OK or +OK+).  All parameters to the NOOP command are ignored.

6.  QUIT Command

          "QUIT" *WS CRLF

     When the client issues the QUIT command, the MTQP session ter-
minates.  The QUIT command has no parameters.  The server MUST respond
with a successful response.  The client may close the session from its
end immediately after issuing this command.

7.  Pipelining

     The MTQP client may elect to transmit groups of MTQP commands in
batches without waiting for a response to each individual command.  The
MTQP server MUST process the commands in the order received.  The fol-
lowing two examples are identical:

     Example #7
     C: TRACK <tracking-id> 1234567890ABCDEF
     S: +OK+ Tracking information follows
     S: ... details go here ...
     S: .
     C: NOOP
     S: +OK Status okay

     Example #8
     C: TRACK <tracking-id> 1234567890ABCDEF

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     C: NOOP
     S: +OK+ Tracking information follows
     S: ... details go here ...
     S: .
     S: +OK Status okay

8.  URL Format

     The MTQP URL scheme is used to designate MTQP servers on Internet
hosts accessible using the MTQP protocol.  An MTQP URL takes one of the
following forms:


     The first form is used to refer to an MTQP server on the standard
port, while the second form specifies a non-standard port.  Both of
these forms specify that the TRACK command is to be issued using the
given tracking id and authorization cookie.  The path element "/track/"
is case insensitive, but the tracking id may not be.

8.1.  MTQP URL Syntax

     This is an ABNF description of the MTQP URL.  Terminal nodes not
defined here are defined in either [RFC-URL] or [RFC-ABNF].

     mtqp-url = "mtqp://" net_loc "/track/" tracking-id ":" cookie

     tracking-id = TBD

     cookie = 16HEXDIG

9.  IANA Considerations

     TBD - registering extensions

10.  Security Considerations

     Security considerations discussed in [RFC-TRACK-MODEL] and [RFC-
TRACK-ESMTP] are relevant.

11.  Protocol Syntax

     This is an ABNF description of MTQP.
     command-response = success-response / temp-response / error-response / bad-response

     temp-response = "-TEMP" opt-text CRLF

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     opt-text = [WSP *(VCHAR / WSP)]

     error-response = "-ERR" opt-text CRLF

     bad-response = "-BAD" opt-text CRLF

     success-response = single-line-success / multi-line-success / multi-char-success

     single-line-success = "+OK" opt-text CRLF

     multi-char-success = "+OK+" opt-text "{" 1*DIGIT "}" *WSP CRLF *OCTET
          ; the number of characters specified by {number} ; must be

     multi-line-success = "+OK+" opt-text CRLF *dataline dotcrlf

     dataline = *998OCTET CRLF

     dotcrlf = "." CRLF

     option-list = *option-line

     option-line = rulename opt-text *[CRLF WSP opt-text] CRLF

12.  References

     [MIME] RFC 2045, N. Freed & N. Borenstein, "Multipurpose Internet
Mail Extensions (MIME) Part One: Format of Internet Message Bodies",
November 1996.

     [RFC-821] STD 10, RFC 821, J. Postel, "Simple Mail Transfer Proto-
col", University of Southern California / Information Sciences Insti-
tute, August 1982.

     [RFC-822] STD 11, RFC 822, D. Crocker, "Standard for the Format of
ARPA Internet Text Messages", University of Delaware, August 1982.

     [RFC-ABNF] RFC 2234, D. Crocker, Editor, and P. Overell, "Augmented
BNF for Syntax Specifications: ABNF", November 1997.

     [RFC-ESMTP] RFC 1651, J. Klensin, N. Freed, M. Rose, E. Stefferud,
and D. Crocker, "SMTP Service Extensions", Silicon Graphics, Inc., July

     [RFC-KEYWORDS] RFC 2119, S. Bradner, "Key words for use in RFCs to
Indicate Requirement Levels", March 1997.

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     [RFC-MD5] RFC 1321, R. Rivest, "The MD5 Message-Digest Algorithm",
April 1992.

     [RFC-TRACK-MODEL] draft-ietf-msgtrk-model-02.txt, T. Hansen, K.
Lin, "Message Tracking Models and Requirements", AT&T Laboratories,
Lotus Development Corporation, ???? 2000.

     [RFC-TRACK-ESMTP] draft-ietf-msgtrk-smtpext-*.txt, E. Allman, "SMTP
Service Extension for Message Tracking", Sendmail, Inc., ???? 2000.

     [RFC-TRACK-TSN] draft-ietf-msgtrk-trkstat-00.txt, E. Allman, "The
Message/Tracking-Status MIME Extension", Sendmail, Inc., ???? 2000.

     [RFC-URL] RFC 1808, R. Fielding, "Relative Uniform Resource Loca-
tors", June 1995.

13.  Authors' Addresses

     Tony Hansen
     AT&T Laboratories
     Lincroft, NJ 07738

     Phone: +1.732.576.3207

14.  Full Copyright Statement

     Copyright (C) The Internet Society (1999).  All Rights Reserved.

     This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or
assist in its implmentation may be prepared, copied, published and dis-
tributed, in whole or in part, without restriction of any kind, provided
that the above copyright notice and this paragraph are included on all
such copies and derivative works.  However, this document itself may not
be modified in any way, such as by removing the copyright notice or
references to the Internet Society or other Internet organisations,
except as needed for the purpose of developing Internet standards in
which case the procedures for copyrights defined in the Internet Stan-
dards process must be followed, or as required to translate it into
languages other than English.

     The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

     This document and the information contained herein is provided on

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     This document expires January 1, 2001.

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