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Open Source Proton Mail Alternatives

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

Proton Mail alternatives are mainly WebMail Providers but may also be Calendar Apps or Email Clients. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of Proton Mail.
This page was last updated Jun 16, 2022
  • FreemiumOpen Source
  • Linux
  • Online
  • Android
  • iPhone
  • iPad
  • Tor

Secure email with absolutely no compromises, brought to you by MIT and CERN scientists.

Learn more about Proton Mail

  1. Tutanota is a free and open source web-mail client that focuses on privacy and security. It has open source iOS and an Android apps.

    Tutanota vs Proton Mail opinions
    Almost everyone thinks Tutanota is a great alternative to Proton Mail.
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    Advik

    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

    Top positive comment  5 months ago
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    2

    Tutanota is a free and open source web-mail client that focuses on privacy. There's also an Android and an iOS app. All data is stored encrypted and can not be searched, i.e. for commercial usage. It offers dead easy end-to-end encryption.

    1 GB of storage is free for everyone. We want to make a secure inbox easily available for everybody worldwide.

    Top positive comment  over 5 years ago
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    9
    UltraProgrammer

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

    Positive comment 10 months ago
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    0
    android037

    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.

    Positive comment 10 months ago
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    0
    prechallenging_despitous

    Cheap easy to use good clint

    Positive comment over 1 year ago
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    0

    Tutanota does not allow immediate access. Must wait 48 hours to use.

    Negative comment about 2 years ago
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    -12
    Belsima

    Functions on secure browsers like Klar and Tor.

    Positive comment about 4 years ago
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    9
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  2. Disroot is a platform providing online services based on principles of freedom, privacy, federation and decentralization.

    Disroot vs Proton Mail opinions
    Almost everyone thinks Disroot is a great alternative to Proton Mail.

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

    Positive comment almost 3 years ago
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    0
    lelgenio

    imap smtp support, open source, all free

    Positive comment about 3 years ago
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    1


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

    Posteo vs Proton Mail opinions
    Almost everyone thinks Posteo is a great alternative to Proton Mail.
    JohnFastman

    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.

    Positive comment about 4 years ago
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    2
  4. mailbox.org offers a secure e-mail account for home and business use. The domain name, me@mailbox.org, is easy to remember and can be understood anywhere in the world. They have been operating e-mail accounts for more than 20 years and are a highly reliable service provider.

    mailbox.org vs Proton Mail opinions
    Almost everyone thinks mailbox.org is a great alternative to Proton Mail.
    JohnFastman

    Mailbox.org is a partial replacement for Protonmail. It offers a fully functional email solution (email, calendar, contacts), but with the added benefits of PGP encryption support (you can handle the keys or let them do it). It also allows you to send links to people who don't use PGP if you want to send private messages. For the encryption, it's a bit like Protonmail. For everything else, it's like a privacy-respecing Gmail alternative.

    Positive comment over 5 years ago
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    2
  5. Criptext

    • Free PersonalOpen Source
    • Mac
    • Windows
    • Linux
    • Android
    • iPhone

    Finally, an email service that's built around your privacy. Get your @criptext.com email address and see what it's like to have peace of mind and privacy in every email you send.

    Discontinued

    Creator recently sent and email about going solo, but since then support has been unresponsive, as have nearly all new issues on github for a year now if not more...

    Criptext vs Proton Mail opinions
    Almost everyone thinks Criptext is a great alternative to Proton Mail.

    Even thought Proton Mail is a good privacy focused email, it still holds both your emails and your keys on their servers. Regarding ownership, Criptext gives the user ownership over their keys, which reside only on the user's devices. It also uses Signal Protocol for encryption which I personally like better than just using pgp.

    Positive comment over 2 years ago
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    3


  6. Kolab Now

    • Online
    • Software as a Service (SaaS)
    • DAVdroid

    Kolab Now provides a suite of intuitive apps in a user friendly environment to make your day to day online comms easier, smarter and most importantly; secure.

  7. FlowCrypt

    • FreemiumOpen Source
    • Android
    • iPhone
    • Google Chrome
    • Brave
    • Firefox
    • OpenPGP

    Simple end-to-end encryption to secure email and attachments on Gmail, Outlook or any other email provider.

  8. systemli.org

    • FreeOpen Source
    • Online

    Systemli.org is a left network and technics-collective that was founded in 2003. Our aim is to provide safe and trustworthy communication services. The project addresses political activists and people who have a particular need to protect their data.

    No screenshots yet
  9. Teknik Mail

    • Online

    Teknik was created to provide users with web services that they can trust. Services range from url shorteners to pastebins and encrypted file uploads.

    No screenshots yet
  10. GPGMail

    • Mac
    • GPGTools
    • Apple Mail

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

    No screenshots yet
Showing 10 of 21 alternatives