Zoho Mail AlternativesOnly Open Source apps categorised as Calendar Apps

The best open source Calendar alternative to Zoho Mail is Proton Mail. If that doesn't suit you, our users have ranked more than 100 alternatives to Zoho Mail and six of them are open source Calendar Apps so hopefully you can find a suitable replacement. Other interesting open source Calendar App alternatives to Zoho Mail are Tuta Mail, Posteo, Infomaniak kMail and Kolab Now.

More about Zoho Mail
Copy a direct link to this comment to your clipboard
Zoho Mail alternatives page was last updated

Alternatives list

  1. Proton Mail icon

    Proton Mail

     1017 likes
    Copy a direct link to this comment to your clipboard

    Proton Mail provides secure email services with end-to-end encryption, ensuring data protection. Swiss-based and outside US jurisdiction, it offers a free version to champion privacy as a human right. Fully accessible on any device.

    98 Proton Mail alternatives

    Cost / License

    • Freemium (Subscription)
    • Open Source

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • iPad
    • Tor
    • Flathub
    • Snapcraft
    Proton Mail screenshot 1
     
    |
    2
    12
    Comments about Proton Mail as an Alternative to Zoho Mail
    Guest
    Negative
    11

    Free plan does not allow your own domain

    Review by a new / low-activity user.
    Serely Lalla
    Positive
    -1

    Encryption and secure service.

    Zoho Mail Icon
    Proton Mail icon

    • Most users think Proton Mail is a great Zoho Mail alternative.

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

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

    • Proton Mail is Freemium and Open SourceZoho Mail is Freemium and Proprietary
  2. Tuta Mail icon

    Tuta Mail

     516 likes
    Copy a direct link to this comment to your clipboard

    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
     
    |
    2
    6
    Comments about Tuta Mail as an Alternative to Zoho Mail
    Guest
    Negative
    3

    Free plan does not allow your own domain

    Review by a new / low-activity user.
    Guest
    Positive
    -1

    Its open source, so its bugs will always be minimal.

    Review by a new / low-activity user.
    Zoho Mail Icon
    Tuta Mail icon

    • Most users think Tuta Mail is a great Zoho Mail alternative.

    • Tuta Mail is Freemium and Open SourceZoho Mail is Freemium and Proprietary
    • Tuta Mail is LightweightZoho Mail is not according to our users
  4. Posteo icon

    Posteo

     83 likes
    Copy a direct link to this comment to your clipboard

    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
     
  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
    Copy a direct link to this comment to your clipboard

    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. Kolab Now icon

    Kolab Now

     42 likes
    Copy a direct link to this comment to your clipboard

    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.

    78 Kolab Now alternatives

    Cost / License

    • Subscription
    • Open Source

    Application types

    Platforms

    • Online
    • Software as a Service (SaaS)
    • DAVx5
    Kolab Now email
     
  8. AfterLogic Aurora icon

    AfterLogic Aurora

     Like
    Copy a direct link to this comment to your clipboard

    Afterlogic Aurora is an enterprise collaboration system for small and medium-sized business. Aurora provides collaboration of webmail, contacts, calendar, files and helpdesk modules.

    Cost / License

    • Pay once
    • Open Source

    Application types

    Platforms

    • Windows
    • Online
    • Android
    • iPhone
    • Self-Hosted
    AfterLogic Aurora screenshot 1
     
6 of 6 Zoho Mail alternatives