wcwells%ucbopal.CC@Berkeley.ARPA (William C. Wells) (02/25/84)
In reply to: Date: Wed, 15 Feb 84 20:47 EST From: "Benson I. Margulies" <Margulies@CISL-SERVICE-MULTICS.ARPA> Subject: envelopes versus messages To: header-people@MIT-MC.ARPA Message-Id: <840216014745.993851@CISL-SERVICE-MULTICS.ARPA> It seems to me that some of the cross purposes of this discussion relate to the role of envelopes. I always have assumed that the content of the envelope is available to the mail agent (mail reading program, if you like) of the recipient. Am I out-to-lunch on that? There is a problem with the definition of envelope. We each seem to have our own definition. "envelope" information, that is information used or added by the mail transport agents, should be passed on to the addressees of a message, but may not be. The mail transport agents job ends when the message has been spooled to (placed in) the addressees mail box. Certain information available to the mail transport agent may not be added to the heading of the message prior to being delivered to the mail box. Trace information and other information added by the mail transport agents should be available to the receiving user agent, though not necessarily displayed by default. In the case of SMTP, much of the SMTP envelope information may also need to be passed on to a non-SMTP mail transport programs in the heading of the message. The information also needs to flow in the opposite direction, from the user agent (the mail formatting/generation program) to the mail transport agent, and in some cases even down to lower levels. For example, the "precedence" and "classification" of a government message is defined by the user agent, but does not look like the RFC 822 or SMTP provides for precedence or classification information to be passed from the user agent down to the IP Header "Type of Service" Precedence bit and the Security field of the IP Header "Security" Option (see RFC 791 section 3.1). Bill Wells wcwells@Berkeley.ARPA ucbvax!wcwells