Open Source Microsoft Exchange AlternativesTop Mail Servers and other similar apps like Microsoft Exchange

The best open source alternative to Microsoft Exchange is hMail Server. If that doesn't suit you, our users have ranked more than 25 alternatives to Microsoft Exchange and 16 is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Microsoft Exchange are mailcow: dockerized, Kolab Community, Zimbra Collaboration Suite and grommunio.

filter to find the best alternatives

Microsoft Exchange alternatives are mainly Mail Servers but may also be WebMail Providers or Calendar Apps.  Other popular filters includes Linux + Free. Filter by these or use the filter bar below if you want a narrower list of alternatives or looking for a specific functionality of Microsoft Exchange.
Microsoft Exchange iconMicrosoft Exchange
  17
  • ...

Exchange business-class email helps increase user productivity while protecting your data. Get it as a hosted service or run it on your servers.

More about Microsoft Exchange
More about Microsoft Exchange
Microsoft Exchange alternatives page was last updated Oct 16, 2024
  Suggest Alternatives
  1. hMail Server icon
    hMail Server icon

    hMail Server

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

    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.

    23 hMail Server alternatives
    hMail Server screenshot 1

    License model

    • Free • Open Source

    Application type

    Platforms

    • Windows

    hMail Server Features

    1.  IMAP Support
    2.  POP3 Support
    3.  SMTP Support
    4.  Convert images to PDF
    hMail Server screenshot 1
    Discontinued

    hMail Server is no longer supported by the people who created it and has been discontinued – so use it at your own risk.

    hMail Server iconMicrosoft Exchange Icon

    hMail Server VS Microsoft Exchange

    Is hMail Server a good alternative to Microsoft Exchange?
     

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

    • hMail Server is the most popular Open Source & free alternative to Microsoft Exchange.

    • hMail Server is Free and Open SourceMicrosoft Exchange is Paid and Proprietary
  2. mailcow: dockerized icon
    mailcow: dockerized icon

    mailcow: dockerized

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

    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.

    21 mailcow: dockerized alternatives
    mailcow: dockerized screenshot 1

    License model

    • Free • Open Source

    Application types

    Platforms

    • Linux
    • Self-Hosted
    mailcow: dockerized screenshot 1
    mailcow: dockerized screenshot 2
    +3
    mailcow: dockerized screenshot 3

    Top mailcow: dockerized Features

    1.  Mail Server
    2.  Self hosted mail
    3. Docker icon  Support for Docker
    4.  ActiveSync
    5.  Dark Mode
    6.  Ad-free
    7.  Two-factor Authentication
    8.  Mail Filtering
    9.  Email Organizer
    10.  Spam Filter
    11.  Support for Aliases
    12.  Modular System
    mailcow: dockerized iconMicrosoft Exchange Icon

    mailcow: dockerized VS Microsoft Exchange

    Is mailcow: dockerized a good alternative to Microsoft Exchange?
     

    • mailcow: dockerized is the most popular Self-Hosted alternative to Microsoft Exchange.

    • mailcow: dockerized is Free and Open SourceMicrosoft Exchange is Paid and Proprietary
  4. Kolab Community icon
    Kolab Community icon

    Kolab Community

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

    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.

    46 Kolab Community alternatives

    License model

    • Freemium • Open Source

    Platforms

    • Linux
    • Online
    • Self-Hosted

    Kolab Community Features

    1.  Real time collaboration
    2.  CalDAV Support
    3.  WebDAV Support
    4.  IMAP Support
    5.  CardDAV Support
    Kolab Community iconMicrosoft Exchange Icon

    Kolab Community VS Microsoft Exchange

    Is Kolab Community a good alternative to Microsoft Exchange?
     
  5. Zimbra Collaboration Suite icon
    Zimbra Collaboration Suite icon

    Zimbra Collaboration Suite

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

    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.

    44 Zimbra Collaboration Suite alternatives
    Zimbra Collaboration Suite screenshot 1

    License model

    • Freemium • Open Source

    Application types

    Platforms

    • Linux
    • Online
    • Self-Hosted

    Zimbra Collaboration Suite Features

    1.  Real time collaboration
    2.  ActiveSync
    3. Microsoft Active Directory icon  Active Directory integration
    Zimbra Collaboration Suite iconMicrosoft Exchange Icon

    Zimbra Collaboration Suite VS Microsoft Exchange

    Is this a good alternative to Microsoft Exchange?
     
  6. grommunio icon
    grommunio icon

    grommunio

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

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

    12 grommunio alternatives
    grommunio screenshot 1

    License model

    • Freemium • Open Source

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
    • Online
    • Android
    • iPhone
    • iPad
    • Self-Hosted
    grommunio screenshot 1
    grommunio screenshot 2

    Properties

    1.  Privacy focused

    Features

    1.  Real time collaboration
    2.  Contacts
    3.  Self hosted mail
    4.  RPC
    5.  Ad-free
    6.  Dark Mode
    7.  Spam Filter
    8. Docker icon  Support for Docker
    9.  CardDAV Support
    10.  IMAP Support
    11.  CalDAV Support
    12.  POP3 Support
    grommunio iconMicrosoft Exchange Icon

    grommunio VS Microsoft Exchange

    Is grommunio a good alternative to Microsoft Exchange?
     
    Comments about grommunio as an Alternative to Microsoft Exchange
     
    Guest

    Great Activesync Support POOR and I mean VERY Poor Calendar that has a mind of It's own, setting events or reminders is a NIGHTMARE

    Positive comment •Oct 16, 2024
    0
    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 •Jun 17, 2021
    2
    Microsoft Exchange Icon
    grommunio icon

    • Almost everyone thinks grommunio is a great Microsoft Exchange alternative.

    • grommunio is the most popular Android, iPhone & iPad alternative to Microsoft Exchange.

    • grommunio is Freemium and Open SourceMicrosoft Exchange is Paid and Proprietary
    • grommunio is Privacy focusedMicrosoft Exchange is not according to our users
  7. Zentyal icon
    Zentyal icon

    Zentyal

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

    Zentyal is a native Microsoft Active Directory implementation on Linux incorporating all the network services required in a small and medium business environment: Directory & Domain Server, Mail Server, Gateway and Infrastructure Server.

    26 Zentyal alternatives
    Dashboard

    License model

    Application types

    Platforms

    • Linux

    Zentyal Features

    1.  Gateway
    2.  Member Directory
    3.  Web interface
    User and Device Management
    Firewall
    +1
    Installation
    Zentyal iconMicrosoft Exchange Icon

    Zentyal VS Microsoft Exchange

    Is Zentyal a good alternative to Microsoft Exchange?
     
    Comments about Zentyal as an Alternative to Microsoft Exchange
     
       
    Guest

    No Exchange alternative and no support for MS Outlook Client

    Negative comment •Mar 5, 2018
    7
    Guest

    Not an Exchange alternative at all. Does basic AD but that is about it. It is more of a gateway server.

    Negative comment •Sep 2, 2019
    0
    Guest

    While the comments below suggest that this is AD, not exchange replacement. It was supposed to ship with SoGo / openchange as a managed add-on. You also strangely enough can't have exchange without AD. but guests do keep on posting. Exchange is just an Add-On to AD. (It extends the schema).

    Positive comment •Aug 7, 2020
    -2
    Show more comments
    3 of 4 comments
    Microsoft Exchange Icon
    Zentyal icon

    • Some users think Zentyal is a great Microsoft Exchange alternative, some don't.

    • Zentyal is Paid and Open SourceMicrosoft Exchange is Paid and Proprietary
  9. Kolab Now icon
    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.

    77 Kolab Now alternatives
    Kolab Now email

    License model

    Application types

    Platforms

    • Online
    • Software as a Service (SaaS)
    • DAVdroid
    Kolab Now calendar
    Kolab Now contacts

    Properties

    1.  Privacy focused

    Features

    1.  Support for Aliases
    2.  Real time collaboration
    3.  End-to-End Encryption
    4.  CalDAV Support
    5.  WebDAV Sync
    6.  CardDAV Support
    Kolab Now iconMicrosoft Exchange Icon

    Kolab Now VS Microsoft Exchange

    Is Kolab Now a good alternative to Microsoft Exchange?
     
    Comments about Kolab Now as an Alternative to Microsoft Exchange
     
    Guest

    With Microsoft no longer supporting our existing setup, this was a great alternative.

    Positive comment •Sep 4, 2015
    2
    Microsoft Exchange Icon
    Kolab Now icon

    • Some users think Kolab Now is a great Microsoft Exchange alternative, some don't.

    • Kolab Now is Paid and Open SourceMicrosoft Exchange is Paid and Proprietary
    • Kolab Now is Privacy focusedMicrosoft Exchange is not according to our users
  10. SOGo icon
    SOGo icon

    SOGo

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

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

    SOGo provides a rich AJAX-based Web interface and supports multiple native clients through the use of standard protocols such as CalDAV, CardDAV and GroupDAV.Share your calendars, address books and mails in.

    63 SOGo alternatives
    SOGo screenshot 1
    SOGo screenshot 2
    SOGo screenshot 3

    License model

    • Freemium • Open Source

    Application type

    Platforms

    • Linux
    • Online
    • Thunderbird
    • Cloudron

    SOGo Features

    1.  Support for Multiple Users
    2.  Scheduling
    3.  CalDAV Support
    4.  CardDAV Support
    SOGo iconMicrosoft Exchange Icon

    SOGo VS Microsoft Exchange

    Is SOGo a good alternative to Microsoft Exchange?
     
  11. OX App Suite icon
    OX App Suite icon

    OX App Suite

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

    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.

    19 OX App Suite alternatives
    OX Portal

    License model

    • Free • Open Source

    Application types

    Platforms

    • Linux
    • Online
    • Self-Hosted
    • Software as a Service (SaaS)
    OX Mail
    OX Address Book
    +6
    OX Calendar

    OX App Suite Features

    1.  Real time collaboration
    2.  Cloud Sync
    3.  Calendar Integration
    4.  Personal Information Manager (PIM)
    5.  Group Mail
    6.  WebDAV Support
    7.  WebDAV Sync
    OX App Suite iconMicrosoft Exchange Icon

    OX App Suite VS Microsoft Exchange

    Is OX App Suite a good alternative to Microsoft Exchange?
     
  12. iRedMail icon
    iRedMail icon

    iRedMail

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

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

    Use official binary packages from Linux/BSD distributions, with both i386 and x86_64 support.

    Easy, fast deployment in LESS THAN 1 MINUTE. View YouTube Video to check how easy it is.

    Works on both no.

    67 iRedMail alternatives
    Main components and working process

    License model

    • Freemium • Open Source

    Application type

    Platforms

    • Linux
    • BSD
    • Self-Hosted
    iRedMail iconMicrosoft Exchange Icon

    iRedMail VS Microsoft Exchange

    Is iRedMail a good alternative to Microsoft Exchange?
     
10 of 16 Microsoft Exchange alternatives