I don’t believe that list. They seem to be giving a list of “free” email providers, but if you look at their references you will see that Proton is supposed to have 50 million accounts of all types (not just email), and of course they have many paid accounts. I would guess that the vast majority of those are VPN services.
When I search through my 20 years of accumulated emails, I can find the following unique users who have sent email to me at the four company Proton domains:
- proton.me — 0
- protonmail.com — 4
- pm.me — 3
- protonmail.ch — 0
I see many more AOL.com addresses than Proton.
Of course, I’m in the US. My assumption is that the list would be completely different in Russia, Egypt, Nigeria, India, China, and Indonesia.
And it’s possible to have a free email account for years and not use it (as long as you have enough activity that it isn’t closed). I have email accounts at yahoo.com, AOL.com, gmail.com, and a few others that I don’t regularly use. I got those accounts so that my own desirable email address was reserved. Use of business and personal domains makes this harder to check.
Bill