This seems to be a FAQ: http://dovecot.procontrol.fi/list/dovecot/2004-February/002959.html
http://www.natalian.org/archives/2004/02/14/maildir/
When you use that maildirmake program or whatever, you need to prefix it with a '.'
Thanks Kai! Now that I understand better the Maildir need, I have another question:
Is ist possible to specify in dovecot.conf that inbox is in mbox format and to use Maildir for the rest of the folders? I remember having seen that somewhere in this same list, but I can't find the message anymore. I think that message said that it was not a supported feature, but the developers were working on it. For now, I don't see any hints in the conf file for configure the env to Maildir+Mbox, so I suppose it's still under development.
I don't want to fiddle much with sendmail, so I'd like to keep the mbox spool as default, but using with Maildir for the other IMAP folders (so as to support subfolders) in dovecot, and convert users' mbox imap folders manually. This would even be a nice feature which would integrate perfectly in new Fedora releases (sendmail mbox drop comes by default) as the configuration would be seamless.
I hope I have explained me correctly.
Thanks in advance again for the replies.
Manuel Moran