A survey of the spam situation on my main Email address:
Orange, my ISP, stores Email in a webmail system before I collect it with my regular Email program, Thunderbird. It has an optional spam filter. Yesterday there were 7644 Emails in its 7 day Junk folder, 45/hour. About 3/hour get through.
There are very few false positives, mostly receipts for shopping online. Orange also seems to use an IP blocking database, so I've had to whitelist a few friends.
What Orange misses are recent spam types such as Image only, so I have my own filter built in to Thunderbird, which reduces that 3/hour to 3/day.
Googling around I found that resetting Bayesian filters and giving them fresh spam to eat can help. So I have, and we'll see if things improve.