According to RFC 2822 section 3.6.4:
The "In-Reply-To:" and "References:" fields are used when creating a
reply to a message. They hold the message identifier of the
original
message and the message identifiers of other messages (for example,
in the case of a reply to a message which was itself a reply). The
"In-Reply-To:" field may be used to identify the message (or
messages) to which the new message is a reply, while the
"References:" field may be used to identify a "thread" of
conversation.
So it certainly isn't a bug, either way. And while the use of the
word "may" means that it isn't required, using "In-Reply-To" appears
to be the way it is generally done. Unfortunately there is no
required way thus clients can use either method. A very non-
scientific polling indicates that apple mail, thunderbird, mutt, and
most likely others use the "In-Reply-To" for threading. Though some
of these may ALSO use the subject. In some cases the subject may be
used to over-ride "In-Reply-To", but not in all cases. Neither is a
bug based on the RFC.
That being said, since it is easier create a new message rather than
modify the "In-Reply-To" header, it is generally asked that new
messages be used so as not to break the threading on clients that use
"In-Reply-To".
Thanks,
Lee
On Aug 29, 2005, at 11:30 AM, Joseph Mack NA3T wrote:
I just replied to Kevin about this. Since I use a mail client that
threads by subject, I wasn't aware that other clients thread by non-
displayed fields. Unless there is something I'm missing, this would
appear to be a bug.
--
TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug
TriLUG Organizational FAQ : http://trilug.org/faq/
TriLUG Member Services FAQ : http://members.trilug.org/services_faq/
TriLUG PGP Keyring : http://trilug.org/~chrish/trilug.asc
