RFC 1652 (rfc1652) - Page 2 of 6

SMTP Service Extension for 8bit-MIMEtransport

RFC 1652                SMTP 8bit-MIMEtransport                July 1994


2.  Framework for the 8bit MIME Transport Extension

   The 8bit MIME transport extension is laid out as follows:

      (1)  the name of the SMTP service extension defined here is
           8bit-MIMEtransport;

      (2)  the EHLO keyword value associated with the extension is
           8BITMIME;

      (3)  no parameter is used with the 8BITMIME EHLO keyword;

      (4)  one optional parameter using the keyword BODY is added to
           the MAIL FROM command.  The value associated with this
           parameter is a keyword indicating whether a 7bit message
           (in strict compliance with [1]) or a MIME message (in
           strict compliance with [3]) with arbitrary octet content
           is being sent. The syntax of the value is as follows,
           using the ABNF notation of [2]:

                body-value ::= "7BIT" / "8BITMIME"

      (5)  no additional SMTP verbs are defined by this extension;
           and,

      (6)  the next section specifies how support for the extension
           affects the behavior of a server and client SMTP.

3.  The 8bit-MIMEtransport service extension

   When a client SMTP wishes to submit (using the MAIL command) a
   content body consisting of a MIME message containing arbitrary lines
   of octet-aligned material, it first issues the EHLO command to the
   server SMTP. If the server SMTP responds with code 250 to the EHLO
   command, and the response includes the EHLO keyword value 8BITMIME,
   then the server SMTP is indicating that it supports the extended MAIL
   command and will accept MIME messages containing arbitrary octet-
   aligned material.

   The extended MAIL command is issued by a client SMTP when it wishes
   to transmit a content body consisting of a MIME message containing
   arbitrary lines of octet-aligned material. The syntax for this
   command is identical to the MAIL command in [1], except that a BODY
   parameter must appear after the address.  Only one BODY parameter may
   be used in a single MAIL command.






Klensin, Freed, Rose, Stefferud & Crocker