Not using /var/spool/mail/ -- Need recompilation?

We are using Qmail instead of sendmail which is designed to be more secure.
 Since /var/spool/mail is always a potential security problem it stores
user's email in $HOME/Mailbox.

I changed /etc/procmailrc to read

ORGMAIL=$HOME/Mailbox
DEFAULT=$HOME/Mailbox

procmail still tries to create /var/spool/mail/$USER file generating an
error message in the mail log.

Procmail does deliver the mail to Mailbox when the user's .procmailrc is
empty.

Why does procmail still try to use /var/spool/mail?  Is there any way
besides recompiling that will convince procmail never to even look at
/var/spool/mail

Thanks.

Yusuf

--
Yusuf Pisan                             [See homepage for PGP public key]
y-pisan(_at_)nwu(_dot_)edu                         http://www.cs.nwu.edu/~yusuf/