RFC # 561 Abhay Bhushan (AKB) MIT-DMCG
NIC # 18516 Ken Pogran (KP) MIT-MULTICS
Ray Tomlinson (RST) BBN-TENEX
Jim White (JEW) SRI-ARC
5 September 73
Standardizing Network Mail Headers
One of the deficiences of the current FTP mail protocol is that
it makes no provision for the explicit specification of such
header information as author, title, and date. Many systems
send that information, but each in a different format. One
fairly serious result of this lack of standardization is that
it's next to impossible for a system or user program to
intelligently process incoming mail.
Although the long-term solution to the problem is probably to
add commands for specifying such information to the mail
protocol command space (as suggested in RFC 524 -- 17140,), we
hereby propose a more quickly implemented solution for the
We suggest that the text of network mail, whether transmitted
over the FTP telnet connection (via the MAIL command) or over a
separate data connection (with the MLFL command), be governed by
the syntax below:
From: White at SRI-ARC
Date: 24 JUL 1973 1527-PDT
Subject: Multi-Site Journal Meeting Announcement
At 10 AM Wednesday 25-JULY there will be a meeting
to discuss a Multi-Site Journal in the context of
the Utility. Y'all be here.
<mailtext> ::= <header> <CRLF> <message>
<header> ::= <headeritem> ! <headeritem> <header>
<headeritem> ::= <item> <CRLF>
<item> ::= <authoritem> ! <dateitem> !
<subjectitem> ! <miscitem>
<authoritem> ::= FROM: <SP> <user> <SP> AT <SP> <host>
<dateitem> ::= DATE: <SP> <date> <SP> <time> - <zone>
<subjectitem> ::= SUBJECT: <SP> <line>
<miscitem> ::= <keyword> : <SP> <line>
<date> ::= <vdate> ! <tdate>
<vdate> ::= <dayofmonth> <SP> <vmonth> <SP> <vyear>
<tdate> ::= <tmonth> / <dayofmonth> / <tyear>
<dayofmonth> ::= one or two decimal digits
<vmonth> ::= JAN ! FEB ! MAR ! APR ! MAY ! JUN !
JUL ! AUG ! SEP ! OCT ! NOV ! DEC
<tmonth> ::= one or two decimal digits
<vyear> ::= four decimal digits
<tyear> ::= two decimal digits
<zone> ::= EST ! EDT ! CST ! CDT ! MST ! MDT !
PST ! PDT ! GMT ! GDT
<time> ::= four decimal digits
<user> ::= <word>
<host> ::= a standard host name
<message> ::= <line> <CRLF> ! <line> <CRLF> <message>
<keyword> ::= <word>
<line> ::= a string containing any of the 128 ASCII
characters except CR and LF
<word> ::= a string containing any of the 128 ASCII
characters except CR, LF, and SP
<CRLF> ::= CR LF
<SP> ::= space
Please note the following:
(1) <authoritem>, <dateitem>, and <subjectitem> may each
appear at most once in <header>; <miscitem> may occur any
number of times. The order of <authoritem>, <dateitem>,
and <subjectitem> is insignificant, but they must proceed
all occurrences of <miscitem>.
(2) The case (upper or lower) of keywords -- specifically,
'FROM', 'DATE', 'SUBJECT' ,'AT', <host>, <zone>, <vmonth>
and <keyword> -- is insignificant. Although 'FROM', for
example, appears in upper-case in the formal syntax above,
in the header of an actual message it may appear as 'From'
(as in the example), or 'from', or 'FrOm', etc.
(3) No attempt has been made to legislate the format of
<user>, except to exclude spaces from it.
(4) The time has no internal punctuation.
(5) No provision is made for multiple authors.
We recommend that mail-sending subsystems which prefix header
information to the text of the user's message be modified
appropriately, and that other hosts recommend the above
conventions to their users.