⚡ Webmail

Webmail software lets users access and manage email directly through a web browser.

It usually includes features like message organization with folders, contact lists, calendars, email filtering, spam protection, and mobile-friendly designs for use on any device.

According to our statistics, webmail software is used on 0.02% of all websites.
99.8% of these sites use only one webmail software solution, 0.2% use two.

Statistics based on 3.3M+ analyzed websites. About this data

⭐ Most Popular in 2026

The following chart shows the leading webmail software in 2026, based on market share.

The most popular is Roundcube, which dominates the market with an overwhelming 62.6% share.
It is followed by Outlook on the web with 14.1% and Mailcow with 11.7%.

✨ Best Webmail Software

Below is a more detailed list of 8 webmail software solutions we detect, ranked by their market share.

RankNameMarket share
1
Roundcube

A browser-based multilingual IMAP client.

FreeOpen source$$$
2
Outlook on the web
Redmond, Washington, United States

A web-based app included in Microsoft 365 that allows users to access their email, calendar, and contacts.
3
Mailcow
Willich, Germany

An open-source groupware/email suite based on Docker.

FreeOpen source
4
RainLoop

An open-source, web-based email client that is no longer being maintained.

FreeOpen sourceLegacy
5
Horde
Atlanta, Georgia, United States

An open-source web-based groupware.

FreeOpen source
6
SOGo
Grenoble, France

An open-source groupware server that provides a rich web interface and supports multiple native clients.

FreeOpen source
7
SquirrelMail

A webmail client written in PHP that includes support for IMAP, SMTP, and a flexible plugin system.

FreeOpen source
8
SnappyMail
Bilthoven, Netherlands

An open-source web-based email client forked from RainLoop.

FreeOpen source

👉 See Also

🗃️ About This Data