New 64bit installation: Exim4 Send to Root

[David Baron <d_baron@012.net.il>]

Logcheck, rkhunter and some others send their email notifications to root. 
Exim4 does no allow emails to root. So root gets aliased and a couple of other 
places are set so that the emails go to another user. I brought the 
configuration files over from the old installation.

I have in /etc/aliases a line root:system_notification
and in /etc/exim4/system.filter lines for saving header with Spam and Virus 
marked to /var/mail/system_notification

Worked before, but not now. What am I doing wrong?