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Best Outlook Web App Alternatives in 2026

Based on real usage data from 0 websites analyzed by StackSee

We analyzed real website data to find the most popular alternatives to Outlook Web App. Outlook Web App is outlook on the web is an information manager web app. It includes a web-based email client, a calendar tool, a contact manager, and a task manager. See which tools teams actually use instead, backed by real-time detection data.

Top Alternatives to Outlook Web App

Technologies in the Webmail category that teams use instead of Outlook Web App, ranked by adoption.

1

CR

CrossBox CrossBox is a webmail client.

Webmail

2

AP

Apple iCloud Mail Apple iCloud Mail is a webmail service provided by Apple, Inc.

Webmail

3

GO

Google Workspace Google Workspace, formerly G Suite, is a collection of cloud computing, productivity and collaboration tools.

WebmailEmail

4

PR

Proton Mail Proton Mail is the world’s largest secure email service with over 70 million users. Available on Web, iOS, Android, and desktop. Protected by Swiss privacy law.

Webmail

5

MI

Microsoft 365 Microsoft 365 is a line of subscription services offered by Microsoft as part of the Microsoft Office product line.

WebmailEmail

6

OP

Open-Xchange App Suite Open-Xchange is a web-based communication, collaboration and office productivity software suite.

WebmailEmail

7

RA

RainLoop RainLoop is a web-based email client.

Webmail

8

RO

RoundCube RoundCube is free and open-source web-based IMAP email client.

Webmail

9

SQ

SquirrelMail SquirrelMail is an open-source web-mail package that is based on PHP language. It provides a web-based-email client and a proxy server for IMAP protocol.

Webmail

10

SY

Sympa Sympa is an open-source mailing list management (MLM) software.

Webmail

11

ZI

Zimbra Zimbra is a provider of open-source email and collaboration software, offering solutions for email, calendar, contacts, and collaboration for both individual and enterprise use.

Webmail