Like peebee I've been getting these for months but use a mail protection program, Mailwasher. Like Warwick I've apparently been spamming myself from places like Kazakhstan (.kz) and one of the UK banks I use apparently has its mail servers in Oregon. I also received the same blackmail threat as Warwick about a month ago and, like him, I don't view porn and they couldn't be "watching" me as I don't have a webcam and my anti-malware detects key loggers and quarantines them until I delete them.
Much of this rubbish comes from a variety of the large number of new Top Level Domains (TLDs) like .business, .fun, .trade, .win, .bid, dozens of others and a variety of countries. A user of the Mailwsher has created a filter that automatically blocks any mail from a domain that a user designates by adding the TLD to the filter.
Mailwasher lets me look at all header information, and much more, on my service provider's mail servers before I even download the mail so it never reaches my system. I can check the sender's IP number, find the location within a few miles and a lot more besides. I've just received an offer of a Tactical Flashlight from the domain "evataclight.xyz", located in Tulsa so I'll add .xyz to the filter and won't see another mail from anyone using any_name.xyz.
Works for me.