What works for individuals and companies doesn't work for ISPs

I use country filters at home too, as part of my filtering. They work really well for filtering email when you know that you are not going to get email from specific countries. This makes them useful for individuals and some sorts of companies.

But for an ISP, or a company that does business globally, they would create too many false positives (filtering desired email). An ISP must assume that his customers contacts can be anywhere in the world, so an ISP cannot implement blanket country filtering (although they could offer it as an option that customers could turn on and off).

To those who make blanket condemnations of country filters, consider white lists and blacklists. My whitelist and my blacklist would be useless to you. And your whitelist and your blacklist would be useless to me. It is the same with country filters.

It is obvious to those of us who use them that you do not filter countries that contain people and businesses you correspond with, and it is obvious that they are not a 100% solution.