Procmail not seeing Variables with sendmail

I have 600 user setup like this so it can't be changed. This is a
legecy system that was using postfix, which i upgraded to sendmail
8.13.6. My problem is it seems like procmail will not use the $HOME
variable or the variables in infprocmail.rc. This worked with
postfix. Why is it a problem to see $HOME. I can't change this to a
..procmailrc because we have a lot of custom .forwards calling all
different types of procmail scripts.

Thanks

"|IFS=' ' && exec /usr/bin/procmail -f- $HOME/infprocmail.rc || exit 75
#ibatch"