Top 12 Horde Alternatives

Web-based IMAP email client

RainLoop is a web based email client.

Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more.

SquirrelMail is a standards-based webmail package written in PHP.

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.

A fully fledged, free email server solution, an open source project (GPL v2).

Kolab Groupware is a secure, scalable, reliable, flexible, full-featured collaboration suite.

Open Source WebMail Lite is a free community edition of full-featured WebMail Pro server applicatio...

Open-Xchange Server 6 is the most advanced Linux based Groupware solution f.

An open source mailserver suite.

All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail.

Zoho Mail is a webmail service built with the needs of a modern business in mind.