Open Source Proton Mail Alternatives Filtered by 'Encrypted Email'

The best open source alternative to Proton Mail is Tuta Mail. If that doesn't suit you, our users have ranked more than 50 alternatives to Proton Mail and nine of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Proton Mail are Disroot, Posteo, Infomaniak kMail and FlowCrypt.

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Proton Mail alternatives are mainly WebMail Providers, but if you're looking for Email Clients or Calendar Apps you can filter on that. Other popular filters include Free, Open Source and Self-Hosted. These are just examples - use the filter bar below to find more specific alternatives to Proton Mail.
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Alternatives list

  1. Tuta Mail icon

    Tuta Mail

     516 likes
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    Offers comprehensive encryption for email, calendar, and contacts with zero personal info required. Built on open source, install via Play Store, F-Droid, or APK, with Tor and VPN support. Both free and paid plans; utilizes quantum-resistant encryption ensuring privacy-focused, anonymous usage.

    103 Tuta Mail alternatives

    Cost / License

    • Freemium (Subscription)
    • Open Source

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • iPad
    • Flathub
    • F-Droid
    Tuta Mail screenshot 1
     
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    10
    153
    Comments about Tuta Mail as an Alternative to Proton Mail
    Comment summary: Tutanota is praised for its affordability and transparency, offering end-to-end encryption and a generous free storage plan that appeals to budget-conscious users. However, users note a wait period for account activation. It is considered user-friendly, though Proton Mail is seen as more secure but pricier. Tutanota encrypts titles and contacts, which some believe gives it an edge in privacy. Overall, it functions well on secure browsers and maintains a straightforward encryption model.
    Top Positive Comment
    Advik
    3

    Tutanota is end-to-end encrypted, as well offers 1 GB mail storage on free plan. The pro plans are cheap compared to protonmail, so it's better for low budget users

    Conner Vieira
    Positive
    -2

    Tutanota has historically been a lot more transparent, and arguably has been more honest about issues and plans

    Ada Byron
    Positive
    1

    I use both, ProtonMail is more secure but also more expensive and not as user-friendly. You cannot beat the price of Tutanota for service they provide.

    Show more comments
    3 of 10 comments
    Proton Mail Icon
    Tuta Mail icon

    • Almost everyone thinks Tuta Mail is a great Proton Mail alternative.

    • Tuta Mail is the most popular Web-based, Windows, Android & Mac alternative to Proton Mail.

    • Tuta Mail is the most popular Open Source & free alternative to Proton Mail.

    • Tuta Mail is Freemium and Open SourceProton Mail is also Freemium and Open Source
    • Tuta Mail is LightweightProton Mail is not according to our users
  2. Disroot icon

    Disroot

     113 likes
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    Disroot is a platform providing online services based on principles of freedom, privacy, federation and decentralization.

    44 Disroot alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Online
    • F-Droid
    Disroot screenshot 1
     
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    3
    23
    Comments about Disroot as an Alternative to Proton Mail
    Leonardo Eugenio
    Positive
    2

    imap smtp support, open source, all free

    Guest
    Positive
    0

    Simple, efficient, you can use it with Tunderbird or other mail client.

    Review by a new / low-activity user.
    Kris22332
    Positive
    -3

    Proton is not confidential at all, because it is under the influence of the EU. The best thing you can find for anonymous messaging and file sharing is the Utopia ecosystem (U.IS)

    Proton Mail Icon
    Disroot icon

    • Almost everyone thinks Disroot is a great Proton Mail alternative.

    • Disroot is Free and Open SourceProton Mail is Freemium and Open Source
  4. Posteo icon

    Posteo

     83 likes
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    Web- and IMAP-based email service. 2GB cost 1€/month. Information is hosted on encrypted hard drives. Electricity from renewable resources is used.

    74 Posteo alternatives

    Cost / License

    • Subscription
    • Open Source

    Application types

    Platforms

    • Online
    Drag and drop
     
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    1
    26
    Comments about Posteo as an Alternative to Proton Mail
    John Fastman
    Positive
    2

    Posteo could be a good Protonmail alternative. It offers email encryption in a similar way: Posteo's people, government surveillance and successful hackers won't get into your email content. It also offers a calendar feature, which protonmail users have been crying out for for years.

    Proton Mail Icon
    Posteo icon

    • Almost everyone thinks Posteo is a great Proton Mail alternative.

    • Posteo is the most popular commercial alternative to Proton Mail.

    • Posteo is Paid and Open SourceProton Mail is Freemium and Open Source
    • Posteo is Security-focusedProton Mail is not according to our users
  5. Ad
    Screenshot
    Infomaniak kMail icon
    Infomaniak kMail

    Privacy-focused Swiss email system provides 20 GB free storage, supports custom domains and unlimited storage, syncs contacts and calendars, is ad-free, and is part of a secure productivity suite used by over a million users acro...

    https://www.infomaniak.com
    Learn More
  6. Infomaniak kMail icon

    Infomaniak kMail

     38 likes
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    Privacy-focused Swiss email system provides 20 GB free storage, supports custom domains and unlimited storage, syncs contacts and calendars, is ad-free, and is part of a secure productivity suite used by over a million users across Europe on all devices.

    42 Infomaniak kMail alternatives

    Cost / License

    • Freemium (Subscription)
    • Open Source

    Application types

    Platforms

    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • F-Droid
    Infomaniak kMail screenshot 1
     
  7. FlowCrypt icon

    FlowCrypt

     17 likes
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    FlowCrypt (formerly CryptUp) is the easiest PGP encryption for Gmail. It behaves just like standard email, except it's encrypted.

    Cost / License

    • Freemium (Pay once)
    • Open Source

    Platforms

    • Android
    • iPhone
    • Google Chrome
    • Brave
    • Firefox
    • OpenPGP
    FlowCrypt screenshot 1
     
  8. Swisscows.email icon

    Swisscows.email

     5 likes
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    Swisscows.email is another product of Swisscows AG. This product offers you secure email traffic. With Swisscows.email you can send your emails encrypted so that absolutely no one can read them. The service is comparable to a letter that is protected from prying eyes in an...

    Cost / License

    • Subscription
    • Open Source

    Application types

    Platforms

    • Online
    • iPhone
    • iPad
    • Android
    • Android Tablet
    Swisscows.email screenshot 1
     
  10. Forward Email icon

    Forward Email

     6 likes
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    Forward Email is the best email service, encrypted email service, and fastest email service. It supports unlimited domains and aliases for no extra cost. It uses quantum safe ChaCha20-Poly1305 encryption and offers SMTP, IMAP, POP3, email webhooks, email regular expressions...

    Cost / License

    • Freemium (Subscription)
    • Open Source

    Application type

    Platforms

    • Self-Hosted
    • Online
    Forward Email screenshot 1
     
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    1
    Comments about Forward Email as an Alternative to Proton Mail
    linuxplayer
    Negative
    1

    Needs an existing email to be used for free. You have to pay to create an email.

    Proton Mail Icon
    Forward Email icon
    • Forward Email is Freemium and Open SourceProton Mail is also Freemium and Open Source
  11. GPGMail icon

    GPGMail

     11 likes
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    GPGMail is a PGP plugin for Apple Mail. It brings the functionality to sign, verify, encrypt and decrypt mails using the OpenPGP standard.

    Cost / License

    • Pay once
    • Open Source

    Platforms

    • Mac
    • GPGTools
    • Apple Mail
     
  12. WebPG icon

    WebPG

     2 likes
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    WebPG is a free, open source suite of tools to bring OpenPGP (GnuPG/PGP, gpg, gnupg) to the browser, in an effort to make cryptographic methods usable, safe and accessible to the common man.

    Cost / License

    • Free
    • Open Source

    Alerts

    • Discontinued

    Platforms

    • Mac
    • Windows
    • Linux
    • Google Chrome
    • Thunderbird
    • SeaMonkey
    • Chromium
    • Firefox
    • OpenPGP
    WebPG screenshot 1
     
9 of 9 Proton Mail alternatives