⚡ Webmail in the United States

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

The United States of America (USA) is a North American country with a population of over 341 million people.

According to our statistics, webmail software is used on 0.01% of websites from the United States.

Statistics based on 579K+ analyzed websites. About this data

⭐ Most Popular in 2026

The following chart shows the top webmail software in the United States in 2026, based on market share.

The most popular is Outlook on the web with an impressive share of 47.6%, followed by Roundcube with 38.1% and Mailcow with 6.3%.

Outlook on the web 47.6%
Roundcube 38.1%
Mailcow 6.3%
Horde 4.8%
SquirrelMail 1.6%
RainLoop 1.6%
SnappyMail 1.6%

🚀 Highlights

Here is a list of the top solutions that is more popular in the United States than worldwide.
Differences between global and country rankings are shown in parentheses.

1. Outlook on the web ^(-1)
4. Horde ^(-2)
5. SquirrelMail ^(-3)

✨ Best Webmail Software

Below is a more detailed list of 7 webmail software solutions used on sites from the United States, ranked by their market share.

Rank	Name	Market share
1	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.	47.6%
2	Roundcube Stuttgart, Germany A browser-based multilingual IMAP client that provides full email access through a web interface with an application-like user experience. FreeOpen source$$$	38.1%
3	Mailcow Willich, Germany An open-source groupware/email suite based on Docker. FreeOpen source	6.3%
4	Horde Atlanta, Georgia, United States An open-source web-based groupware. FreeOpen source	4.8%
5	SquirrelMail A webmail client written in PHP that includes support for IMAP, SMTP, and a flexible plugin system. FreeOpen source	1.6%
6	RainLoop An open-source, web-based email client that is no longer being maintained. FreeOpen sourceLegacy	1.6%
7	SnappyMail Bilthoven, Netherlands An open-source web-based email client forked from RainLoop that provides fast, lightweight access to IMAP and SMTP mail servers through a browser. FreeOpen source	1.6%

👉 See Also

🌎 Webmail in other countries

🗃️ About This Data

We evaluate the popularity of technologies based on the number of websites where we detect their usage.
Technologies without a detectable web footprint, and those we do not track, are not reflected in the calculated market share.
This report is based on the analysis of 579,597 websites from the United States.
We currently track the presence of 8 webmail software solutions across the web.
Of these, 7 were detected on websites from the United States.
Statistics were last calculated on May 6, 2026.
For more details, see our methodology and disclaimer.