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Free Microsoft Exchange Server Alternatives

The best free alternative to Microsoft Exchange Server is Kopano, which is also Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to Microsoft Exchange Server and many of them is free so hopefully you can find a suitable replacement. Other interesting free alternatives to Microsoft Exchange Server are hMail Server, mailcow: dockerized, Zimbra Collaboration Suite and Kolab Community.

Microsoft Exchange Server alternatives are mainly Mail Servers but may also be WebMail Providers or Calendar Apps. Filter by these if you want a narrower list of alternatives or looking for a specific functionality of Microsoft Exchange Server.
This page was last updated Jun 17, 2021
  • Windows
  • Online

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the...

Learn more about Microsoft Exchange Server

  1. Kopano

    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • Android Tablet
    • Windows Phone
    • iPad
    • Self-Hosted
    • Microsoft Office Outlook
    • S/MIME
    • Software as a Service (SaaS)

    Kopano puts an email, video meetings, calendaring, and file sharing solution within one single interface.

    Kopano vs Microsoft Exchange Server opinions
    Almost everyone thinks Kopano is a great alternative to Microsoft Exchange Server.
    hn1

    Kopano has scalable backend and can do full MAPI server and clientside. The Webapp and Deskapp has intuitive and modern UI/UX.

    Top positive comment  over 5 years ago
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    0
    bobsp

    Scalable, open source with a great UX and it has all the features I need

    Top positive comment  over 5 years ago
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    marcski

    Stable and cheap backend, flexible frontend support, open source, in full control of your data

    Positive comment over 5 years ago
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    0

    OpenSource, better to maintain, "not Microsoft"

    Positive comment over 5 years ago
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    -1

    I tried a lot of MS alternatives, OX, Zimbra, Zentyal, but what fits most with Outlook Sync was the new Kopano, it's more flexible. You can use the web app or desktop app too.

    Positive comment over 5 years ago
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    -1
  2. hMailServer is a free e-mail server for Microsoft Windows. Its used by Internet service providers, companies, governments, schools and enthusiasts in all parts of the world.

    Almost everyone thinks hMail Server is a great alternative to Microsoft Exchange Server.


  3. mailcow: dockerized

    • FreeOpen Source
    • Linux
    • Self-Hosted

    mailcow is a mail server suite based on Dovecot, Postfix, SOGo, Rspamd and other open source software, that provides a modern Web UI for administration.

  4. Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more. With the most innovative web application available today, Zimbra boosts the productivity of users on any desktop and dramatically reduces TCO compared to legacy platform vendors.

    Most users think Zimbra Collaboration Suite is a great alternative to Microsoft Exchange Server.
  5. Kolab Community

    • FreemiumOpen Source
    • Linux
    • Online
    • Self-Hosted

    Kolab is entirely Free and Open Source Software (a.k.a. FOSS), and uses Open Standards. We’ll get to why this is important to us, and hope that it is important to you thereafter.

    No screenshots yet
    Most users think Kolab Community is a great alternative to Microsoft Exchange Server.


  6. SOGo

    • FreemiumOpen Source
    • Linux
    • Online
    • Thunderbird
    • Cloudron

    SOGo is groupware server with a focus on scalability and open standards.

  7. iRedMail

    • FreemiumOpen Source
    • Linux
    • BSD
    • Self-Hosted

    A fully fledged, free email server solution, an open source project (GPL v2).

  8. OpenChange

    • FreeOpen Source
    • Linux

    OpenChange aims to provide a portable Open Source implementation of Microsoft Exchange Server and Exchange protocols.

    No screenshots yet
  9. OX App Suite

    • FreeOpen Source
    • Linux
    • Online
    • Self-Hosted
    • Software as a Service (SaaS)

    The OX App Suite by Open-Xchange is web-based platform offering a suite of apps like an email client, calendar, contacts magement, cloud storage with synchronization and productivity apps for word processing, spreadsheets and presentations.

  10. grommunio

    • FreemiumOpen Source
    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • iPad
    • Self-Hosted

    grommunio (formerly known as grammm) efficiently combines all requirements of modern, digital communication and collaboration.

    grommunio vs Microsoft Exchange Server opinions
    pros, cons and recent comments
    norbertlambing

    As the first open source solution to offer a full-featured OutlookAnywhere (RPC over HTTP) and MAPI/HTTP implementation, grammm is the alternative to proprietary backends for native interoperability with Microsoft Outlook

    Positive comment about 1 year ago
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    1
Showing 10 of 20 alternatives