Its an impressive and reliable service that is protected by the firm legal privacy laws in Switzerland.
End-to-end encryption is the order of the day, and ProtonMail requires no personal data to create your account, including your IP address that could be used to track your location. The software is open-source, with SSL, AES, RSA and OpenPGP encryption technologies deployed throughout.
One of the problems often encountered with secure services is that they can suffer from a lack of convenience. ProtonMail sidesteps this by allowing you to choose from a variety of uses, included secure email to other ProtonMail users or third-party service (ie Gmail, etc.) via a password that you send separately to decrypt messages.
There’s also the option to send normal, unencrypted messages to third-party users if you’re not worried about the government finding out about Thursday’s five-a-side meetup. The choice is made in the email via the Encrypt button, making ProtonMail a very usable solution in most situations.
Another useful feature is the ability to create email addresses that end in pm.me rather than protonmail.com. This is free to all users, although to be able to reply with the former you’ll need to sign up to one of the paid plans.
At the time of writing this will cost you €4 per month for the Plus tier that allows you to send and receive 1000 messages per day, offers 5GB of storage, multiple folder support, an autoresponder feature, and customer support. You can also increase the storage for additional small fees, add a VPN, or try one of the other tiers for even more features.
The free tier grants 500MB of storage, limits the account to 150 messages a day, and only has support for three folders, but it’s a good way to try out the service before investing any money.