using procmail to deliver to $HOME/<filename>

[Jim Breton <jamesb-debian@alongtheway.com>]

I've looked in teh procmail man pages (potato) and can't find for the
life of me why this isn't working.

I'm running qmail on my machine with a default mailbox of $HOME/Mailbox.
However, I have one user who wants to use procmail for his deliveries.

So in his .qmail file we put this:

|/var/qmail/bin/preline /usr/bin/procmail

and in ~/.procmailrc:

     MAILDIR=$HOME/mail   # all mailboxes are in mail/
     DEFAULT=$MAILDIR/Mailbox
     SHELL=/bin/sh

But procmail is determined to try to write to /var/spool/mail:

qmail: 961599665.328538 delivery 4663: success: procmail:
_Couldn't_create_"/var/spool/mail/greg"/did_0+0+1/


Why isn't procmail heeding the $DEFAULT variable and writing to this
user's home directory?

(I had removed the suid bit from /usr/bin/procmail because qmail runs
procmail as the userid, does this matter?)

Thanks.