These emails also tend to end with something like “if you’d rather not be emailed, simply reply with stop, no hard feelings” and are invariably followed up a day or two later if you simply ignore them.

Because adding to a blocklist is generally more effort than it’s worth to me, I have an email signature which simply says “Please stop emailing me”, nothing else, no “hello”, no sign off, just an (appropriately) completely cold one liner response to them.

Not memorable enough that I’d burn any bridges in my future, but also uses as little of my time as possible while they get a completely unambiguous message of what I want them to do.

I then use my mail provider’s report spam button.