Quoting Graham Trott gt@pobox.com:
I'd like to do something similar but using different criteria based on a list of approved sender addresses.
Have you looked at ASK (Active Spam Killer) and TMDA (Tagged Message Delivery Agent)? I have used ASK in the past, and required my spam to about 1 a week. TDMA was a bit over the top for what I wanted at the time, so I went with ASK, which takes all of about 5 minutes to setup.
One downside is that some people think an email saying 'I WILL NOT GET YOUR MESSAGE UNLESS YOU REPLY TO THIS - yadda yadda explination yadda' doesn't apply to them, or they get confused. In my opinion though, this is a good thing, I don't want to talk to people who can't understand that.
Happy Bank Holiday!
Ian P. Christian