Ths project is in active development and has been built with AI.
Unicorn Webmail is a lightweight, high-performance webmail client built in PHP, designed for modern hosting platforms and custom control panels. It focuses on speed, scalability, and IMAP efficiency, avoiding the traditional bottlenecks found in legacy webmail solutions.
Instead of repeatedly querying the IMAP server for every view, the client maintains a local SQLite index of message metadata, allowing instant message listing, searching, and filtering while keeping IMAP interactions minimal and predictable.
Eventually this will be built into the Unicorn Control Panel ecosystem. Traditional webmail clients tend to:
- Re-query IMAP on every page load
- Perform server-side sorting on large mailboxes
- Become unusably slow at scale
- RoundCube and other webmail variants do not handle multi-accounts well, if at all
This project flips that model by treating IMAP as the source of truth, while using a local index as a read-optimized cache, resulting in:
- Instant inbox loads
- Predictable IMAP usage
- Better UX on large mailboxes
- A clean base aimed at multi-account webmail users