On Thu, 22 Mar 2007, John C Klensin wrote:
In Section 4.4 on Trace Information, the "ID" clause of the Received field is
ID = CFWS "ID" FWS String / msg-id
This is claimed to be inconsistent with RFC 2822, which only permits msg-id.
I believe this was a bug fix in 2821, since 821 only allows <string> and
822 only allows <msg-id>. Many MTAs (the most popular ones) only use the
historically-correct <string> syntax, though my archive of this list shows
a number use the new 2821 syntax.
"String" is there to provide additional flexibility for gateways, etc., for
which a message-ID format may not be appropriate, but it has been suggested
that we remove it in the interest of consistency.
That would be incompatible with a lot of running code.
f.a.n.finch <dot(_at_)dotat(_dot_)at> http://dotat.at/
VIKING: SOUTHEASTERLY 4 OR 5, OCCASIONALLY 6. MODERATE. OCCASIONAL RAIN.
MODERATE OR GOOD.