Alternatives to Horde for all platforms with any license

Gmail

Gmail is a free search-based web-mail service. It offers a full featured web-based email client with search capabilities, a mailbox with Pop and IMAP access, SPAM...

Free Personal Web Android iPhone Chrome OS Android Tablet ... iPad Android Wear Android TV
Collaborative writing IFTTT integration Support for IMAP Integrated Chat ... Integrated Spam Protection Add a feature

2902 Like
Roundcube

Roundcube webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an e-mail client...

Free Open Source Self-Hosted PHP Cloudron
Hostable PGP Encryption Add a feature

138 Like
Mailpile

Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features. The development of Mailpile is funded by a large community of backers and...

Free Open Source Mac Windows Linux Web Self-Hosted ... OpenPGP
POP3 Support Add a feature

100 Like
Zoho Mail

Zoho Mail is a webmail service built with the needs of a modern business in mind. It provides features for business users to communicate effectively while catering to...

Freemium Web Android iPhone
Custom domain Ad-free Integrated Spam Protection Mail filtering ... POP3 Support Privacy focused SMTP integration Two factor authentication Add a feature

77 Like
Rainloop

Simple, modern & fast web-based email client. Modest system requirements, decent performance, simple installation and upgrade, no database required. All these make...

Free Open Source Self-Hosted JavaScript PHP Cloudron
Encrypted email Add a feature

42 Like
Squirrelmail

SquirrelMail is a standards-based webmail package written in PHP. It includes built-in pure PHP support for the IMAP and SMTP protocols, and all pages render in pure...

Free Open Source Self-Hosted PHP
On-premises software Add a feature

23 Like
Zimbra Collaboration Suite

Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more. With the most innovative web application available today, Zimbra...

Commercial Linux Web
ActiveSync Real time collaboration Add a feature

28 Like
Webmail Lite

Open Source WebMail Lite is a free community edition of full-featured WebMail Pro server application intended for users who need a clean and simple web mail...

Free Open Source Web Self-Hosted
No features added Add a feature

15 Like
mailcow: dockerized

mailcow is a mail server suite based on Dovecot, Postfix, SOGo, Rspamd and other open source software, that provides a modern Web UI for administration.

Free Open Source Linux
Support for Docker Add a feature

19 Like
iRedMail

A fully fledged, free email server solution, an open source project (GPL v2). Use official binary packages from Linux/BSD distributions, with both i386 and x86_64...

Free Open Source Linux BSD Self-Hosted
Email Server Add a feature

16 Like
Teknik Mail

We provide these services to help those who try to innovate. In order to register a new account, you will need to input a valid invite code during registration. This...

Free Open Source Web
Support for IMAP POP3 Support Add a feature

2 Like
Cypht

All your E-mail, from all your accounts, in one place. Cypht is like a news reader, but for E-mail. Cypht does not replace your existing accounts - it combines them into...

Free Open Source Self-Hosted
Built-in RSS reader End-to-end encryption Modules POP3 Support Add a feature

4 Like
Inboxer

Unofficial, free and open-source Google Inbox Desktop App. Built using electron, Inboxer includes a menu bar which is globalmenu compatible and works, and keyboard...

Free Open Source Mac Windows Linux
No features added Add a feature

1 Like
Atmail Email Server

Atmail webmail system offers a webmail client, email server platform and mailserver appliance for Linux, Unix and Windows. Features: Webmail Calendar Addressbook ...

Commercial Linux Web
File-sync Group Mail Add a feature

7 Like
NOCC

NOCC is a webmail client written in PHP. It provides webmail access to IMAP and POP3 accounts.

Free Open Source Web
POP3 Support Add a feature

4 Like