[Dovecot] Moving from mbox to maildir?

Hi all,

New to the list. I have an updated FC4 box with Dovecot version 0.99.14.4.fc4. My mbox size is about 76 megs and growing rapidly because of several high-volume mailing lists I'm subscribed to. I have noticed that over time the performance of the Evoluion/Spamassassin/Dovecot combo deteriorates. Someone on the Fedora users list suggested I have a look at moving to a maildir setup. Reading the docs I can't really figure out what to. Does anyone have a suggestion how I can safely move my mbox setup to a maildir setup? Much appreciated!

Regards, Patrick