PrivMX WebMail
Alternative, self-hosted private mail system. End-to-end encryption for messages and attachments. Easy to install and administration. Allows also to create end-to-end encrypted web forms.
Horde
Horde Groupware is a free, enterprise ready, browser based collaboration suite. Users can manage and share calendars, contacts ...
Squirrelmail
SquirrelMail is a standards-based webmail package written in PHP. It includes built-in pure PHP support for the IMAP and SMTP ...
Rainloop
Simple, modern & fast web-based email client. Modest system requirements, decent performance, simple installation and upgr ...
Roundcube
Roundcube webmail is a browser-based multilingual IMAP client with an application-like user interface. It provides full functi ...