newbie: procmail question /var/mail

[admin]

Hi,

Okay I have read some tutorial sites on procmail but want to make sure I have
some things clear here before I move everybody plus some things I dont quite
understand are happening and I cant find relevant infromation.  

/var/mail is filling up quickly.   I am attmepting to migrate /var/mail/<user>
files to a new scheme that places the DEFAULT local delivery to something like
$HOME/Mailbox .

I am using procmail for local delivery and sendmail is the agent.

in sendmail I have the following from the <hostname>.mc file.

--- snip ---
define(`PROCMAIL_MAILER_PATH',`/usr/local/bin/procmail')dnl
FEATURE(local_procmail,`',`/usr/local/bin/procmail -t -Y -a $h -d $u')dnl
--- snip ----

okay but I have a few users with $DEFAULT defined to /var/mail/<user> so I am
trying to figure out a way to gracefully handle this without creating the need
for a flag day and have the need to have every user redefine their $DEFAULT .

I thought I could just have a soft symlink from /var/mail/<user> to
$HOME/Mailbox .  but every new message delivery replaces /var/mail/<user> and
then generates a /var/mail/BOGUS.<user>.ca 

I guess this can be asked somewhere else like a procmail list but well this
list has a lot of good information in the past.  Should I go to the procmail
lists for support or can somebody help me here?

- Noah