[Dovecot] Smooth mailbox to maildir migration

[Luciano Mannucci]

Hi all,

I have a postfix+procmail+dovecot installation, now running basicaly
on pop3 hence mailbox format, with few thousand users and less than
twenty gigabytes mail.
I need to move all of them to maildir, to take advantage of IMAP
subfolders that do not work with mbox format (so I'm told :).
Of course I cannot safely stop the service for more than a bunch of
seconds...

What I'm about to do:

create a second dovecot instance to cope with imap client configured
for maildir (and possibly pop3 on another port for those using both),
which means a dovecot launched with -c /path/to/alternate.conf and a
new /etc/init.d/dovecot2-theRevenge having the proper -i option given
to startproc in order to make it ignore the other instance.

for each user:

convert the mailbox with some sort of mb2mb (which is the better one?)

create a .procmailrc with a proper DEFAULT= bearing the magic trailing
slash indicating maildir to procmail for each converted user.

And I'm done...

Have I forgotten something?
Is there a better way?
Any one else tryed such a thing?

Cheers to all,

luciano.
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