RFC # 561
NIC # 18516
Abhay Bhushan (AKB) MIT-DMCG
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 NIC: 17996

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.

        Formal Syntax:                                               
           <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.