[Dovecot] mbox to maildir batch conversion

Hello,

I'm upgrading my mail server from UW to Dovecot and I'd like to convert from mbox to maildir. I've successfully convert myself and a few other users with the mb2md script. All is well.

My question is, I have somewhere around 500 users and about 122gb of mail folders to convert (this does not include the inbox at /var/mail).

mb2md needs to be run as each user to convert. Are there any programs or scripts out there that will allow me to convert everyone at the same time?

I know there is a Dovecot plugin to convert mail, but we didn't want to use this option.

I'm sure someone on this list was in the same situation as me, how did you handle a massive conversion?

Any help or suggestions is much appreciated!