RoundCube Mail

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, including MIME support, address book, folder manipulation, message searching and spell checking.

Features

Available in over 70 languages

Drag-&-drop message management

Full support for MIME and HTML messages

Sophisticated privacy protection

Compose messages with attachments

Multiple sender identities

Full featured address book with groups and LDAP connectors

Find-as-you-type address book integration

Richtext/HTML message composing

Forwarding messages with attachments

Searching messages and contacts

Threaded message listing

IDNA support

Spell checking

IMAP folder management

Shared/global IMAP folders

Support for external SMTP server

Support for access control lists (ACL)

Built-in caching for fast mailbox access

Unlimited users and messages

Template system for custom skins

Plug-in API for flexible exensions

Horde

Horde Groupware Webmail Edition is a enterprise ready, browser based communication suite. Users can read, send and organize email messages and manage and share calendars, contacts, tasks and notes with the standards compliant components from the Horde Project.

Features

IMAP and POP3 webmail client
Message filtering
Message searching
HTML message composition with WYSIWIG editor
Spell checking
Built in attachment viewers
Encrypting and signing of messages (S/MIME and PGP)
Quota support
Keyboard navigation
Full character set support for folders names and email messages
Conversation view of all messages in a thread

Folder tree in left menu pane
Message previews in mailbox view
Downloading of message attachments in a ZIP file
Fetching of messages from external email accounts
Flexible, individual alias addresses
IMAP folder subscriptions
Shared IMAP folders
Graphical emoticons
Support for mailing list headers
Forwarding of multiple messages at once
Attachments sent as links

SquirrellMail

SquirrelMail is a standards-based webmail package written in PHP

SquirrelMail includes built-in pure PHP support for the IMAP and SMTP protocols

SquirrelMail renders in pure HTML 4.0 (with no JavaScript required) for maximum compatibility across browsers

SquirrelMail has very few requirements and is very easy to configure

SquirrelMail has all the functionality you would want from an email client, including strong MIME support, address books, and folder manipulation

Webmail Clients

Features