5 open source alternatives to Gmail

5 open source alternatives to Gmail

Gmail has enjoyed phenomenal success, and regardless of which study you choose to look at for exact numbers, there's no doubt that Gmail is towards the top of the pack when it comes to market share. For certain circles, Gmail has become synonymous with email, or at least with webmail. Many appreciate its clean interface and the simple ability to access their inbox from anywhere.

But Gmail is far from the only name in the game when it comes to web-based email clients. In fact, there are a number of open source alternatives available for those who want more freedom, and occasionally, a completely different approach to managing their email without relying on a desktop client.

Let's take a look at just a few of the free, open source webmail clients out there available for you to choose from.


First up on the list is Roundcube. Roundcub is a modern webmail client which will install easily on a standard LAMP (Linux, Apache, MySQL, and PHP) stack. It features a drag-and-drop interface which generally feels modern and fast, and comes with a slew of features: canned responses, spell checking, translation into over 70 languages, a templating system, tight address book integration, and many more. It also features a pluggable API for creating extensions.

It comes with a comprehensive search tool, and a number of features on the roadmap, from calendaring to a mobile UI to conversation view, all sound promising, but at the moment these missing features do hold it back a bit compared to some other options.

Roundcube is available as open source under the GPLv3.


Roundcube screenshot courtesy of the project's website.


The next client on the list is Zimbra, which I have used extensively for work. Zimbra includes both a webmail client and an email server, so if you’re looking for an all-in-one solution, it may be a good choice.

Zimbra is a well maintained project which has been hosted at a number of different corporate entities through the years, most recently being acquired by a company called Synacore, last month. It features most of the things you’ve come to expect in a modern webmail client, from webmail to folders to contact lists to a number of pluggable extensions, and generally works very well. I have to admit that I'm most familiar with an older version of Zimbra which felt at times slow and clunky, especially on mobile, but it appears that more recent versions have overcome these issues and provide a snappy, clean interface regardless of the device you are using. A desktop client is also available for those who prefer a more native experience. For more on Zimbra, see this article from from Zimbra's Olivier Thierry who shares a good deal more about Zimbra's role in the open source community.

Zimbra's web client is licensed under a Common Public Attribution License, and the server code is available under GPLv2.



I have to admit, SquirrelMail (self-described as "webmail for nuts") does not have all of the bells and whistles of some more modern email clients, but it’s simple to install and use and therefore has been my go-to webmail tool for many years as I’ve set up various websites and needed a mail client that was easy and "just works." As I am no longer doing client work and shifted towards using forwarders instead of dedicated email accounts for personal projects, I realized it had been awhile since I took a look at SquirrelMail. For better or for worse, it’s exactly where I left it.

SquirrelMail started in 1999 as an early entry into the field of webmail clients, with a focus on low resource consumption on both the server and client side. It requires little in the way of special extensions of technologies to be used, which back in the time it was created was quite important, as browsers had not yet standardized in the way we expect them to be by today’s standards. The flip side of its somewhat dated interface is that it has been tested and used in production environments for many years, and is a good choice for someone who wants a webmail client with few frills but few headaches to administer.

SquirrelMail is written in PHP and is licensed under the GPL.


SquirrelMail screenshot courtesy of the project website.


Next up is Rainloop. Rainloop is a very modern entry into the webmail arena, and its interface is definitely closer to what you might expect if you're used to Gmail or another commercial email client. It comes with most features you've come to expect, including email address autocompletion, drag-and-drop and keyboard interfaces, filtering support, and many others, and can easily be extended with additional plugins. It integrates with other online accounts like Facebook, Twitter, Google, and Dropbox for a more connected experience, and it also renders HTML emails very well compared to some other clients I've used, which can struggle with complex markup.

It's easy to install, and you can try Rainloop in an online demo to decide if it's a good fit for you.

Rainloop is primarily written in PHP, and the community edition is licensed under the AGPL. You can also check out the source code on GitHub.


Rainloop screenshot by author.


The next webmail client we look at is Kite, which unlike some of the other webmail clients on our list was designed to go head-to-head with Gmail, and you might even consider it a Gmail clone. While Kite hasn't fully implemented all of Gmail's many features, you will instantly be familiar with the interface. It's easy to test it out with Vagrant in a virtual machine out of the box.

Unfortunately, development on Kite seems to have stalled about a year ago, and no new updates have been made to the project since. However, it's still worth checking out, and perhaps someone will pick up the project and run with it.

Kite is written in Python and is licensed under a BSD license. You can check out the source code on GitHub.

More options

  • HastyMail is an older email client, originating back in 2002, which is written in PHP and GPL-licensed. While no longer maintained, the project's creators have gone on to a new webmail project, Cypht, which also looks promising.
  • Mailpile is an HTML 5 email client, written in Python and available under the AGPL. Currently in beta, Mailpile has a focus on speed and privacy.
  • WebMail Lite is a modern but minimalist option, licensed under the AGPL and written mostly in PHP.
  • There are also a number of groupware solutions, such as Horde, which provide webmail in addition to other collaboration tools.

This is by no means a comprehensive list. What's your favorite open source webmail client?

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