[Dovecot] How to use deliver to deliver to virtual users

Hi,

Ok, here's my setup, each virtual user has a home directory as follows:

/virtusers/

and per the INBOX directive in the dovecot.conf file I also have a file as follows:

/var/mail/

Now, I've followed the directions as outlined here: http://wiki.dovecot.org/LDA/Sendmail

But every time I send mail to one of my virtual users, I get this message

The original message was received at Sat, 5 Jan 2008 14:22:51 -0700 (MST) from wa-out-1112.google.com [209.85.146.183]

----- The following addresses had permanent fatal errors ----- /var/mail/jdunkin (reason: Can't create output) (expanded from: jdunkin@whitneybaptist.org)

----- Transcript of session follows ----- 550 5.0.0 /var/mail/jdunkin... Can't create output

What could I be missing?

Andy