Undo tag operation?

[Alex Ghitza]

Dear notmuch folks,

I just inadvertently removed the "todo" tag from all my "todo"-tagged
emails (about 60 of them going back several months, so I doubt I can
find them all again in my email haystack).  So I have a few questions:

1. Is there currently an easy way to undo this?
2. Is there currently a complicated, maybe-won't-work way to undo
this?  I have not touched the emacs instance, nor the notmuch
database, since the incident, if that helps.
3. If the answers to both 1 and 2 are "no" (which is what I expect),
should notmuch itself (or the emacs frontend) have an undo
possibility?

Best,
Alex

--
Alex Ghitza -- Lecturer in Mathematics -- The University of Melbourne
-- http://aghitza.org