So, I've started dorking with the LWZ threading algo
(http://www.jwz.org/doc/threading.html) and something somewhat unrelated
smacked me on the head: msgIDs suck.

For the uninitiated, Celeste assigns an unique id to each mail message it
stores and uses these ids for a good chunk of it's functionality. E.g.,
Categories are basically just named collections of these ids. Alas, these
ids are unique only to the particular Celeste. From MailDB>>nextUnusedID:

"Each message needs to have a unique ID.  Message ID's are a monotonically
increasing integers roughly related to the time that they were
requested.  The last ID used is kept in lastIssuedMsgID, to guard against
reuse (e.g. if the clock changes)."

Thus, unless I'm confused or mistaken, I cannot share a categorization of
a number of messages with someone else without sharing the particular
message file (or subset thereof).

That kinda sucks!

I'm not quite sure what to do about this. Ideally, the Message-ID header
would be ubiquitous and correct...but I suspect it gets garbled. I suppose
some sort of heuristic thingy that preserved this as much as possible
yadda yadda yadda checksums yadda yadda mappings yadda yadda yadda.

Just wondering if anyone else felt this and if so (or even if not) what
are folks thoughts on solving this.

Cheers,
Bijan Parsia.