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
Integrated Chat IFTTT integration Support for IMAP Integrated Search ... Integrated Spam Protection Mail filtering Multiple Account support Organize mails Outlook integration Suggested replies Threaded Conversations Unified inbox Web-Based Yahoo Integration Add a feature

2968 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

141 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 Web-Based Add a feature

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

82 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

44 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

26 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...

Freemium Open Source Linux BSD Self-Hosted
No features added Add a feature

19 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...
- Similar scope of groupware functionality, including calendar, tasks, etc. sondrak • Mar 2019
Commercial Linux Web
Active Directory integration ActiveSync Real time collaboration Team Collaboration Add a feature

28 Like
Isotope Mail Client

Microservice based webmail client built with ReactJS and Spring. Minimalistic webmail client which currently has the main features of any other mail client (read...

Free Open Source Mac Windows Linux Web Self-Hosted ... Kubernetes Docker OpenShift
Autocompletion Support for Docker Dockerized Drag n drop ... No database needed Rich text editing Web-Based Add a feature

1 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
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
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

3 Like
Net-C

European, full and secure mail system: antispam, automatic sorting, webmail, mobile app, OpenPGP encryption. Choice of e-mail address in the following domain names:...

Freemium $ $ $ Web Android iPhone Android Tablet Windows Phone ... iPad OpenPGP
ActiveSync Gpg encryption Support for IMAP PGP Encryption ... POP3 Support Privacy focused Support for WebDAV Add a feature

2 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...
- Discontinued Project archived. See https://github.com/denysdovhan/inboxer/issues/101
Free Open Source Mac Windows Linux
No features added 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 Apps with End-to-End Encryption Modules POP3 Support Add a feature

4 Like