[Dovecot] reading subfolders with mail.app

Hi all,

I have been having a hard time using Fedora Core 4 with dovecot +sendmail. Namely, I cannot read my home dir's procmail filtering dir
(where I have some subfolders) in ~/mail. I cannot create mailboxes
either. I'm wondering if this is a client issue, and whether I need
to switch to Maildir, which I'd like to do, but don't know how to
with sendmail (with postfix, it's a piece of cake).

Any advice on what my problem is? I'm all ears!

regards,

Patrick