[Dovecot] Problem getting new mail from Postfix to Dovecot

Dear reader,

I am having problems getting new mail into my Inbox. I have this in my dovecot.conf:

default_mail_env = maildir:~/Maildir:INBOX=/var/mail/%u

The logs show nothing special, catting /var/mail/%u shows the new mails coming in, as does /var/log/mail.info

Any clues?

Regards, Dave.