Ok, I figured this out.
Actually this is not a registry hack as I thought I remembered, but it is a
command in powershell using the SCLJunkThreshold.

This link explains it:
http://exchangepedia.com/blog/2007/0...how-to_07.html

"GauiC" wrote in message
...
I found out one day that you could change the SCL of what messages will be
moved to Junk E-mail folder in Outlook.
Does anyone know how this is done and also what is the default SCL level
that is filtered to junk E-mail folder?

GC