Proposed Mail Protocol (RFC0524)
Original Publication Date: 1973-Jun-13
Included in the Prior Art Database: 2001-Nov-15
Internet Society Requests For Comment (RFCs)
THE MAIL PROTOCOL ENVIRONMENT
Network Working Group J. White
Request for Comments: 524 SRI-ARC
NIC: 17140 13 June 1973
A Proposed Mail Protocol
This is the document I offered in (15146,) to write. It's a proposed
specification for handling mail in the Network -- a Mail Protocol.
Main handling is currently implemented as two FTP commands, MAIL and
MLFL, which permit an FTP user process to deliver a file or string of
text to an FTP server process, designating it as mail to be made
available to a user, identified by a local name, in its host. The
protocol proposed here is much richer than that, both in terms of the
functions it supports, and in terms of the flexibility it provides.
Although one can (I think) and might, implement software on the basis
of this document, this REALLY IS a Request for Comments. Comments,
questions, position papers are solicited. There are, I'm sure, bugs
in the protocol specified here, and I hope that readers will point
them out via RFC as they discover them.
Various members of the Network community have, during the last few
months, pointed out to me specific inadequacies in the existing mail
commands and asked me to be conscious of them in designing a new
protocol. I've tried to do that. If anyone feels that his concern
wasn't properly dealt with here, or that it slipped through the
cracks entirely (for which I apologize in advance), I would
appreciate it if he would prod me once more.
THE MAIL PROTOCOL ENVIRONMENT
The Mail Protocol (MP) is implemented by Mail user and server
processes, in keeping with the model for previous high-level
protocols. The Mail user and server processes are further
specified to be also FTP user and server processes, respectively.
That is, MP is implemented as a set of commands accessible from
within the FTP command space.
The MP command set is defined to lie conceptually within a
subsystem, invoked from the FTP command space with the command
White [Page 1]
RFC 524 A Proposed Mail Protocol 13 June 1973
NOTE: Since a command called 'MAIL' already exists within the
FTP command space, the command name 'XMAIL' might substitute
for 'MAIL' while the current mail commands are being phased
The MP command set may or may not (according to the implementation
of a particular server) be implemented by a process distinct from
that which implements FTP proper.
The following are implications of the 'subsystem' concept, of
which the reader (and implementer) must be aware:
(1) Names of MP commands are known only within the MP
subsystem. MP commands must (and should naturally) be rejected
by the server if the user process presents them outside of the
(2) Exit from the Mail subsystem (to the FTP command space) is
effected with and only with the command EXIT <CRLF>. FTP
commands must be rejected by the server if the user presents
them while inside the subsystem (i.e., before EXIT is issued).
(3) The same command name may be assigned without ambiguity to
two entirely different comman...