[Dovecot] Move to a Specific Folder

[Andrew Schulman]

> Will this solution works even if I had a lot of messages or subfolders?

Of course, if you know how to use the find(1) command.  Test it carefully
before you deploy it, though-- find | xargs rm is an extremely dangerous
combination, since you'll probably need several iterations to get the find
conditions right.

> Will this index update take much time?

I can't say for sure.  All I can say is that I've never noticed any
significant delay.  If you run the job daily, then index updates might be
smaller and take less time.  Even if Dovecot has to rebuild the whole
index, you could probably arrange to make that happen right after you run
your deletion job, at off hours.  A search for "dovecot rebuild index"
turns up some discussion of this problem.

Good luck,
Andrew.