SquirrelMail is a webmail package. It has all the functionality you would want from an email client, including strong MIME support, address books, and folder manipulation.
SquirrelMail outputs valid HTML 4.0 for its presentation, making it compatible with a majority of current web browsers. SquirrelMail uses a plugin architecture to accommodate additional features around the core application.
It includes built-in pure PHP support for the IMAP and SMTP protocols, and all pages render in pure HTML 4.0 (with no JavaScript required) for maximum compatibility across browsers.
It has very few requirements and is very easy to configure and install.
SquirrelMail is stable enough to use in a production system, and is very popular with educational organisations.
SquirrelMail allows you to log in to your IMAP and SMTP servers using plaintext, CRAM-MD5 or DIGEST-MD5, as well as use SSL for extra security.
Features include:
- Composing, sending and receiving emails.
- Supports HTML email, pure text.
- Search function.
- Mail filtering.
- Folders.
- Address books.
- Calendars.
- Threading.
- Automatic forwarding.
- Multiple mailboxes.
- Supports IMAP (tested with Binc IMAP, Courier-IMAP, Cyrus IMAP, DBMail, Dovecot, MailServer, Mercury IMAP, and UW IMAP).
- POP3 support.
- Connect to an IMAP server via SSL.
- Use the software in an intranet.
- LDAP Address Book support.
- Works with any Mail Transfer Agent via SMTP.
- Extra features are available in the form of plugins:
- Over 200 third-party plugins are available: Plugins for S/MIME and GPG/OpenPGP, Virtual Host, New Mail and many more.
- Translated into over 40 languages.
Website: squirrelmail.org
Support: Documentation
Developer: Alex Lemaresquier, Alexandros Vellis, Chris Hilts, Fredrik Jervfors, Jonathan Angliss, Marc Groot Koerkamp, Paul Lesneiwski, Seth E. Randall, Steve Brown, Thijs Kinkhorst, and many contributors
License: GNU General Public License v2.0
SquirrelMail is written in PHP. Learn PHP with our recommended free books and free tutorials.
Return to Web-Based Email Clients
| Popular series | |
|---|---|
 | The largest compilation of the best free and open source software in the universe. Each article is supplied with a legendary ratings chart helping you to make informed decisions. |
 | Hundreds of in-depth reviews offering our unbiased and expert opinion on software. We offer helpful and impartial information. |
 | The Big List of Active Linux Distros is a large compilation of actively developed Linux distributions. |
 | Replace proprietary software with open source alternatives: Google, Microsoft, Apple, Adobe, IBM, Autodesk, Oracle, Atlassian, Corel, Cisco, Intuit, and SAS. |
 | Awesome Free Linux Games Tools showcases a series of tools that making gaming on Linux a more pleasurable experience. This is a new series. |
 | Machine Learning explores practical applications of machine learning and deep learning from a Linux perspective. We've written reviews of more than 40 self-hosted apps. All are free and open source. |
 | New to Linux? Read our Linux for Starters series. We start right at the basics and teach you everything you need to know to get started with Linux. |
 | Alternatives to popular CLI tools showcases essential tools that are modern replacements for core Linux utilities. |
 | Essential Linux system tools focuses on small, indispensable utilities, useful for system administrators as well as regular users. |
 | Linux utilities to maximise your productivity. Small, indispensable tools, useful for anyone running a Linux machine. |
 | Surveys popular streaming services from a Linux perspective: Amazon Music Unlimited, Myuzi, Spotify, Deezer, Tidal. |
 | Saving Money with Linux looks at how you can reduce your energy bills running Linux. |
 | Home computers became commonplace in the 1980s. Emulate home computers including the Commodore 64, Amiga, Atari ST, ZX81, Amstrad CPC, and ZX Spectrum. |
 | Now and Then examines how promising open source software fared over the years. It can be a bumpy ride. |
 | Linux at Home looks at a range of home activities where Linux can play its part, making the most of our time at home, keeping active and engaged. |
 | Linux Candy reveals the lighter side of Linux. Have some fun and escape from the daily drudgery. |
 | Getting Started with Docker helps you master Docker, a set of platform as a service products that delivers software in packages called containers. |
 | Best Free Android Apps. We showcase free Android apps that are definitely worth downloading. There's a strict eligibility criteria for inclusion in this series. |
 | These best free books accelerate your learning of every programming language. Learn a new language today! |
 | These free tutorials offer the perfect tonic to our free programming books series. |
 | Linux Around The World showcases usergroups that are relevant to Linux enthusiasts. Great ways to meet up with fellow enthusiasts. |
 | Stars and Stripes is an occasional series looking at the impact of Linux in the USA. |