SquirrelMail was founded in 1999 by Luke Ehresman and Nathan Ehresman. The project was created to provide a simple, lightweight, PHP-based webmail client that could work with standard IMAP servers.
SquirrelMail quickly became popular due to its:
- Simplicity: Minimal interface, easy to deploy
- PHP-based: No compilation required, easy installation
- IMAP support: Worked with any standard IMAP server
- Low resource usage: Suitable for shared hosting environments
Key milestones:
- 1999: First release
- 2000: Version 1.0 stable release
- 2002: Version 1.2 with plugin architecture
- 2004: Version 1.4 series begins
SquirrelMail became one of the most widely deployed webmail solutions:
- 2005: Version 1.4.5 with improved security
- 2006: Version 1.4.8 with better Unicode support
- 2008: Version 1.4.13 with security improvements
- Widely bundled with hosting control panels (cPanel, Plesk)
- Default webmail for many Linux distributions
¶ Decline and Discontinuation (2011-2025)
The project entered a long decline:
- 2011: Last major release (v1.4.22, July 12, 2011)
- 2012-2016: Minimal maintenance, security patches only
- 2016: Copyright notice frozen at 2016
- 2019: cPanel deprecated SquirrelMail in favor of Roundcube
- 2021: PHP 8 compatibility announced for nightly snapshots (no stable release)
- 2025: Officially discontinued on August 4, 2025
SquirrelMail was known for:
- Pure PHP: No dependencies beyond PHP and IMAP
- Simple interface: Basic HTML 4.0, works on all browsers
- Plugin system: Extensible through plugins
- GPL-2.0 license: Open source
SquirrelMail’s impact on webmail:
- Pioneered PHP-based webmail clients
- Made webmail accessible on shared hosting
- Inspired successors like Roundcube
- Served as many users’ first webmail experience
As of 2026:
- Status: ❌ Discontinued (August 4, 2025)
- Last release: v1.4.22 (July 12, 2011)
- Copyright: Frozen at 2016
- Recommendation: Migrate to Roundcube or other maintained alternatives
| Version |
Year |
Key Features |
| 1.0 |
2000 |
First stable release |
| 1.2 |
2002 |
Plugin architecture |
| 1.4 |
2004 |
Improved IMAP support |
| 1.4.8 |
2006 |
Unicode support |
| 1.4.22 |
2011 |
Final release |