ProtonMail is a popular and highly-respected email provider that offers excellent privacy. I have written before about the advantages of ProtonMail. See http://bit.ly/2wfhD6G for a list of my past articles about ProtonMail.
Now ProtonMail has introduced a new feature that apparently has been requested for some time. In order to improve privacy even more, customers may now pay for ProtonMail accounts by using Bitcoin, the semi-anonymous (see the footnote below) cryptocurrency. Quoting from the ProtonMail Blog at https://protonmail.com/blog/bitcoin-secure-email/:
“Starting from version 3.11 of ProtonMail, it is now possible to pay for premium ProtonMail secure email account using Bitcoin. We have designed the payment system to work seamlessly so that Bitcoin payments are automatically converted to ProtonMail credits which can be used to pay for upgrades, pay invoices, or top up your account. This feature was long overdue, so we are glad to finally introduce this.