Date: 2005-08-28 15:28
From: Frank Ellermann <nobody(_at_)xyzzy(_dot_)claranet(_dot_)de>
Bruce Lilly wrote:
Part of the problem is UAs which suppress message header
fields, caused by the proliferation of "noise" fields in the
message header (initially SMTP "Mail-From", subsequently
renamed "Received", and now including a large number of
others).
s/Received/Return-Path/ (or is this some pre-821 history ?)
RFC 821's predecessor, RFC 788:
The time stamp line and the return path line are formally
defined as follows:
<return-path-line> ::= "Return-Path:" <SP><reverse-path><CRLF>
<time-stamp-line> ::= "Mail-From:" <SP> <stamp> <CRLF>
<stamp> ::= [<ptcl>] <from-host> <this-host> <daytime>
...
Ordinary users are most probably not often interested in the
timespamp lines, and MUAs not showing them in their default
configuration are fine.
Interesting typo; maybe the lines should in fact be referred to as
"timespam".
The problem with UAs suppressing header fields is that some of them
suppress important fields which communicate information from the
message originator to recipients (e.g. Reply-To). The SMTP precedent
of modification of the message (header) content after leaving the
originator has directly led to other modifications (List- fields
and a plethora of X- fields) which in turn have led to the practice
of suppressing display of fields. It's a tough problem for a UA
author, as there is no way to automatically determine whether some
new message header field is a new originator field (which should not
be suppressed) or some transport noise (which should be suppressed).
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