Arnt Gulbrandsen <arnt(_at_)gulbrandsen(_dot_)priv(_dot_)no> writes:
Charles Lindsey writes:
Therefore, I would suggest using something based on the MIME
parameters, such as
Annotations: classification=top_secret;
archived-at="http://foo.example/123456";;
x-spamassassin-score=5
Note that this scheme is fundamentally incompatible with IMAP. In IMAP,
message headers are invariant. Once a client has downloaded a
particular field, it can cache that forever, so that field can never
change. (Search for msg-att-static in the IMAP RFC.)
You probably don't want any mail system extension to be fundamentally
incompatible with IMAP...
In IMAP, you can download the message, add or modify Charles' header,
upload the message again, and delete the old message. I believe
superseding in news would work in a similar fashion. That solution
isn't incompatible with IMAP.
The fact that this operation may be inefficient is a problem with
IMAP, not with the header. The sometimes obnoxious design of IMAP can
be incompatible with, otherwise reasonable, solutions, in some cases.
I'm not saying I think Annotations: is a good idea, though. I think
it is better to use one header for each purpose, than to create a
generic purpose kitchen sink.
Regards,
Simon