On Tue, 8 May 2007, Arnt Gulbrandsen wrote:
...
I'd also be inclined to *not* talk about case-sensitivity and comparisons
since nowhere is it discussed in 2822.
Agree. I can't even think of a way to count what the running code does.
There are two places it matters: in the copying of message-ids for replies
and in the implementation of threading algorithms.
If a MUA generating a reply were to try to 'clean up' the message-ids in
the parent that use the obsolete syntax (because it wants its reply to
match the generate syntax), then the MUA needs to only strip CFWS and
tweak quoting and not get carried away and normalize case too.
On the threading side, well, draft-ietf-imapext-sort-18 says
Note: Message ID comparisons are case-sensitive.
so this issue is covered from that angle. Actually testing threading
implementations outside of IMAP would be laborious...
Philip Guenther