viewing duplicate messages

[Rollins, Jameson]

This is essentially a wishlist report...

It would be nice to have an easy way in notmuch-emacs-show to know if
there are multiple messages with the same message-id in the store, and
to cycle through viewing each individually.

It's possible (even likely) that one has multiple messages with the same
message-id in their mail store.  For example, this can happen when sent
messages are saved with an fcc and the same message is received on a
mailing list.  Notmuch indexes all copies, but it only shows you one of
the copies when you ask to view the message.

This behavior would be fine if all copies of the message were identical.
But it's more likely that the copies are in fact different, for example
because the mailing list has altered the received message in some way,
it was mangled in transit, or someone is explicitly trying to attack
your mail store [0].

It would be nice to have better exposure of the fact that multiple
copies exist, and to have an easy way to view alternate copies.  For
notmuch-emacs a key could just cycle through available copies.

jamie.

[0] https://notmuchmail.org/pipermail/notmuch/2012/009965.html