My procmail script is set up to junk all emails with a score over 10.0 and
other "low spammy" emails are directed to a generic corporate spam email
account for review. Depending on the volume of email, you may not want to
wait 3 months. I check mine weekly and typically have close to 2000 emails.
And those are just the ones with low scores. Prior to junking "high spammy"
emails my volume was double that in a day.

I'd share my script, but for fear of people trashing the configuration I
wont. I am bad at scripting, so it is clunky but works...