Wow, Mr. David. Thanks for the time and energy you put into this post. The thing is, I guess you must think you're writing to someone who understands what you wrote!
When I go the the rules page, there are only three topics, and at the bottom is where I found "edit" and "customize." When I went to that page, I got the impression that I had to know code.
I know nothing about code.
I use three main addresses, and even though I am diligent about "teaching" FastMail where things are supposed to go, emails rarely get sent to the right place. I checked the rule about where the newsletters and commercial dealings go, and they [b]are[b] set up properly. (Newsletters have always been a problem. Apparently, here in Texas some organizations just refuse to recognize FastMail. I can't ever get their newsletters with any FM address and have finally set up a Zoho account for many of them. What can I say? It's Texas.)
But as for the spam, I need to find that page where I can type in the exact words(without code) I want FM to completely reject. I never want them to come to me even as spam. I don't understand what a "score" is or how to assign one.
It's like one day someone opened a bizarre, kinky warehouse of unrelated products, and all of them send me multiple emails all at the same exact time. These emails are arriving in batches, not one or two trickling in. There are sometimes over 20 of them.