7 Best Open Source Web-based Email Clients

Email services are here to stay, even if decentralized tech takes over the internet.

However, with big tech trying to control everything new aspect of emerging technologies, how can you take charge of your email service?

Whether a business/enterprise or an individual, a self-hosted open-source webmail service is always an option worth considering. Your server, your digital infrastructure, and your email service platform. This way, you do not have to rely on a vendor or a third party to manage your email services. You do it your way.

Why Should You Self-Host an Email Service?

It is not a one-click process to self-host a service, which you can use as a web-based email client or sync with an email app.

So, why bother? Can’t you use some of the best privacy-focused email services like Proton Mail and Tutanota?

Well, yes, you can.

But, for businesses and enterprises, some advantages of self-hosting webmail include:

• The user gets total control over email data.
• You get the ability to build your infrastructure that meets the requirements of your email services.
• It provides scalability for individuals, small businesses, and enterprises.
• You can create unlimited email accounts and email aliases.
• Users can easily apply advanced filters and other protection mechanisms without paying for a subscription.

Here, I list some of the best options that you can pick.

1. Roundcube

Key Highlights:

• Good fit for desktop use
• Actively maintained
• Available with most server hosting providers
• Customizable UI
• PGP Encryption

Roundcube is a popular PHP-based webmail software that provides all the essential features in a simple user interface.

With most of the server hosting providers, you already get it pre-installed. You have to configure it for your domain or create email accounts to get started.

You can also install it and customize it on your server.

2. Cypht

Key Highlights:

Cypht is an interesting webmail solution that provides a combined view of multiple email accounts.

While it is built with a modular approach, it is easy to add functionalities to your experience with plugins.

Unlike others, you can also use it to add RSS feeds and utilize it as a newsreader.

3. Squirrelmail

Key Highlights:

• Lightweight
• Stable
• PGP Encryption plugin support

A classic PHP-based with IMAP and SMTP protocol support. It does not include many features, but it gets the basics right if you want lightweight and stable webmail software to host.

While it looks like a barebone implementation, it has been around for a long time with features like address book, folder manipulation, and MIME support.

It also comes bundled in with most web hosting providers.

4. Rainloop

Key Highlights:

• No database required
• Simple user interface
• Lightweight

Rainloop is a straightforward email solution that supports IMAP and SMTP protocols.

It also supports OpenPGP encryption. Unlike some others, it does not require a database. Direct access to the mail server is maintained without requiring storing anything locally on the web server.

You can extend certain functionalities thanks to plugin support.

5. Horde

Key Highlights

• Bundled with web hosting providers
• Simple and feature-rich

Horde is an open-source groupware webmail software that comes bundled with various web server hosting providers. It supports IMAP.

I usually prefer Horde when accessing the webmail for my domains, which has never disappointed me. It offers a simple and effective user interface and many essential features.

Like others, it is a PHP-based framework that makes it easy for developers to work with.

6. SOGo

Key Highlights:

• Material design UI
• Outlook support
• Online demo available

SOGo is a modern open-source solution that features Google’s material design UI with its email server.

It includes support for calendar and address books while providing a friendly AJAX-based web interface.

You also get support for Microsoft Outlook and ActiveSync, which lets you synchronize emails, contacts, events, and tasks seamlessly. An online demo is available for you to try. If it sounds good, you can download it for your server.

Explore more about it on its GitHub page.

7. Afterlogic WebMail Lite

Key Highlights:

• Enterprise support options are available
• Social sign-in support
• OpenPGP Encryption

An interesting open-source webmail with plugin support.

It supports authentication using external services as well. For instance, you can use your Google account to sign in to your email account.

While you get all the features and OpenPGP encryption support with the open-source edition, you can choose to use it commercially as well.

Additionally, you can opt for the pro version to get technical support, a priority fix, a personal calendar, a mobile version, and the ability to add multiple IMAP accounts.

Interesting Mentions

Several open-source projects are under active development that you can experiment with.

Of course, we do not recommend using them for business or personal use. You can try them out to see if you want to contribute to their development in some way.

I would like to mention a couple of such mail service projects.

Mailpile

While it deserves a spot in the list above, the development for Mailpile has halted until Python3 rewrite is complete.

It is a fast and modern open-source webmail with encryption and privacy-centric features.

Cuttlefish

Cuttlefish is a free and open-source transactional email service. It aims to be an alternative to proprietary services like SendGrid.

It is in its early stages of development.

Pinbox

A self-hosted webmail solution that gets its inspiration from Google Inbox.

Pinbox a work in progress and needs a few prerequisites to make it work.

Wrapping Up

Squirrelmail, Horde, and Roundcube remain of the most popular options that can be easily accessed with most hosting providers.

Of course, these options are not always modern looking or have features like Google Workspace or even Zoho but you get enough to do the necessary emailing.