On Thu, Oct 15, 2026 at 11:42 +0800, Kevin J. McCarthy wrote:
Add the concept of a "message identifier" - naming ideas welcome. It
know this is a little too close to message-id and could be confusing.
For Maildir/mh it's the path inside the mailbox.
For IMAP it's the UID.
For POP3 it's the refno.
mbox doesn't currently implement anything.
Sounds reasonable, but here's an idea about a better name.
That doesn't identify a message; it identifies a storage location of a
message. (There could be many stored copies of a message.) Maybe it
could be called storage location, or storage identifier. It should not
be called a message identifier.
To be complete, it should include an identifier of the folder, along
with the identifier within that folder. (For example, the folder ID
would be needed for the recent request about a notmuch search.) The
folder identifier would be a pathname for a local folder, but something
else for an IMAP or POP folder -- a URL, I guess.
A message doesn't always have a storage location, because it's not
always stored. It's not in any storage when it's sent across the
network through SMTP. Also, it's possible to send a message through a
Unix pipe, or even send a whole folder, if the folder is a single
sequential file like mbox. (There's a program named mboxgrep that does
that kind of thing.)
Either or both of the folder identifier and identifier within that
folder, could be missing.
