That was already in the back of my mind for a while. I've been subscribed to the emerging threats thread on the forum. I had not acted on it yet because I do not trust my understanding of this to a level that I would mess around with the system too much. Especially as I have to look into firewall groups and because this kind of blocking is handled very low in the system (so it never shows up in the GUI, I think).
But now I have decided to add the emerging threat blacklist to my system, possibly add my own list from attacks I see on my mail server.
I downloaded a script mentioned in that thread, but it did not run.
It would be great if Ubiquiti covered this in EdgeOS.
G