fixing duplicate UID errors when using mbsync and mu4e

[Ben M. <ben...@gm...>]

I was having persistent errors about duplicate UIDs when I was syncing with
mbsync while using mu4e as my email client. After a lot of digging around I
found the solution was in the mbsync and mu4e manuals (of course). Anyway,
I though I would post it here even though it is a mu4e fix, since some
might come across it thinking (as I did initially) that the problem was
with mbsync.

The problem is caused because mu4e does not by default rename files when
moving them to a new directory. This is easily fixed by adding

(setq mu4e-change-filenames-when-moving t)

to your mu4e config in emacs.

Cheers,
 Ben