--On Monday, 14 March, 2005 11:11 +0100 Arnt Gulbrandsen
Bruce Lilly writes:
It might make sense to put transport-related additions (trace
fields, List- fields, etc.) in a separate place ("envelope")
distinct from the end-to-end, user-to-user message header
(date, to/from/cc, subject, etc.).
Either way, it's something different from what we have now.
It does sound a bit like an S/MIME message, doesn't it?
And like X.400. And, to a limited extent (motivated by trying
to maintain compatibility), like
draft-klensin-email-envelope-00. The abstract from that draft
During the last few years, a number of proposals for
extensions or improvements to email have run into trouble
with a side-effect of mail relaying. In the current
Internet Mail model, every SMTP server is required to
break strict layering by inserting one or more additional
"trace" headers into the message headers which are
actually part of the SMTP payload. Since the headers are
altered in transit, header-signing is not an available
option, various anti-spam and internationalization
strategies are infeasible or much more complex, and so on.
This document proposes to change the Internet mail model
to place the in-transit trace information in the envelope,
removing the requirement that relaying systems modify the
The draft was posted a year ago last January and long expired:
find your friendly archive or convince me that this discussion
is likely enough to go somewhere that I should repost it. I've
got a never-posted revision that, among other things, clarifies
the downgrading mechanism (but it is pretty obvious). So far,
the amount of traction the idea has gotten is consistent with a
fairly clear answer to the sanity check remark at the end of the
introduction. Unless there is evidence to refute that
conclusion, or at least a more persuasive draft, the discussion
about getting headers into the envelope is probably a waste of
time. In other words, from my point of view at least, this
would be a good idea, and we could do it --although certainly
not overnight. We just do not, in practice, care.