Download websites that use Proton Mail

About Proton Mail

A website does not run Proton Mail. The domain behind the website does, and keeping that distinction in view changes how the row should be read. Proton Mail is an encrypted mail service from Proton AG, launched in 2014 and sold on a Freemium basis, and detection here means a domain routes its inbound mail to Proton rather than that anything on the page was built with it. We file the entry under Webmail for exactly that reason.

As of September 2026 we see 601,081 domains routing mail this way, 303,676 of them in United States, with .com common across the set. The spread is wider than the provider's Swiss base would suggest, which is itself informative, because encrypted mail is bought for a stance rather than for proximity.

Putting a custom domain on Proton is a deliberate act with a price attached, since custom domain support sits on the paid side of the line. A domain in this list is therefore a paying customer, and usually a small organisation whose founders treated confidentiality as a requirement rather than a nice extra. Law practices, journalism outfits, medical and counselling services, security consultancies, and privacy focused software companies are heavily represented in that shape of decision. Domains in the group rarely sit alongside a large corporate mail suite, because moving an established enterprise onto Proton is a far harder project than starting there on day one.

Two kinds of reader want the whole population rather than a single answer. Vendors selling privacy adjacent products get a group that has already paid for privacy once, which is a strong qualification signal and one that no interest based targeting can reproduce. Competing mail providers get the same group for displacement, with a clear sense of what objection they will meet. Researchers and journalists get a way to measure whether appetite for encrypted communication is growing, flat, or shifting between markets, and a question phrased that way only exists at the level of the full set. Checking the mail records for one domain takes seconds and answers nothing beyond that domain.

The limits are straightforward and worth respecting. Mail routing shows where messages arrive and says nothing about where they are sent from, so a domain can receive at Proton while a marketing platform sends in its name from somewhere else entirely. Records also lag reality at both ends of a migration, because the change becomes visible only when the records themselves are updated. And a listed domain reveals nothing about how many mailboxes sit behind it, so a solo consultant and an entire firm look identical in this data.