How to debug ~/.forward

How can I debug ~/.forward file or see errors logged by mail agent on it **without root privileges**? I'm trying to process my mail with procmail. When I invoke procmail manually with procmail < testMailFile it works as expected (my procmail rule logs input to a file). When no ~/.forward file is present all mail goes to my default mailbox /var/mail/$USER and ~/.procmailrc **is not processed**. When I create ~/.forward with: "|exec /usr/bin/procmail || exit 75" mail stops coming but .procmailrc **is still not processed**. $ lsb_release -a|grep Desc Description: CentOS release 5.10 (Final) $ rpm -q exim exim-4.63-10.el5