As of September, 2022:
The free tier of Proton Mail includes 1 email address, 3 folders and labels, and up to 150 messages per day. You pay nothing for this tier, and it includes enough features for most average users including 1 GB of storage.
Proton Mail Plus: $3.99/month
If you’re looking for something a little more scalable, then the Proton Mail Plus tier is right for you. It includes 15 GB of storage, up to 10 different email addresses, and unlimited folders, labels, filters, and messages. You also get one custom email domain to use. For example, your email address could be “[email protected]” instead of the standard “[email protected]”. You will also have access to Proton Calendar & priority support from the Proton team. You get all of these features for just $3.99 USD per month!
Proton Unlimited: $9.99/month
Last but not least, we have the Proton Unlimited plan. This is the most popular tier because you get a ton of features for only $9.99 USD per month. This includes a whopping 500 GB of storage, 15 email addresses, unlimited messages, and up to 3 custom email domains. In addition to those features, you also get access to Proton Calendar, Proton Drive, AND Proton VPN. You also get the same priority support on top of everything else.