Switching to maildir problem

["Guy McArthur" <guymac@gmail.com>]

Greetings, I've tried switching to maildir on a small debian server.
Qmail was working perfectly until this.

I changed /etc/init.d/qmail from

alias_empty="|/usr/sbin/qmail-procmail"

to

#alias_empty="./.maildir/"

My .maildir is (I think) created properly using the maildirmake
command from courier-imap.

Local delivery works to the maildir.

However, all messages from outside are now bounced with an error like
Sorry,_no_mailbox_here_by_that_name ... username-username@hostname

Somehow, procmail must have been doing something extra to resolve my
username, does anyone know what that would be and how I can implement
it with a maildir delivery?

Thanks.