As far as I know, every other mail client lets you create rules based on if the message body contains certain words. I notice things getting through my spam filters because of new domains, or shared domains, and that's bad. There are certain words that are always going to be considered spam to people, so it doesn't matter where they come from. Even if you think it's not a great way to create a rule, I think you should give us the option, especially since your refuse to let us quickly add to existing filters. As an example, I get emails from Substack that I either did not sign up for but every time I get one of those, I have to add the subdomain manually, or create a new rule for it, or sometimes I get emails that I did sign up for, but the content of that email is one I wouldn't want in my inbox. If I could set keywords or phrases in the filter, these issues would not exist.