Atmail is a fully-featured email server and Webmail client, allowing users to send and receive email via a Web browser or mobile device. It has full support for IMAP mailboxes, and an optional email-server mode that uses EXIM as the MTA. Features include a scheduler, MySQL backend support, spell-check, address book, calendar user preferences, multiple accounts, SpamAssassin support, migration scripts from other mail servers, a customizable interface, an attractive AJAX interface, an optional group sharing Calendar/Addressbook, and an Outlook plugin to sync Contacts/Tasks/Calendar data between a Desktop, Mobile, and Webmail client or other email users.
EMEXIS WEBMAIL is a Webmail application based on SquirrelMail. SquirrelMail client is a complete Webmail system, but due to the concern of making it compatible with many browsers and systems, its interface has become a little impaired. EMEXIS WEBMAIL was developed with the intention of solving this deficiency. It comes with all functionality of the original Squirelmail, but with an interface that is much more friendly for the user. It mostly uses the mechanisms for handling messages from Squirrelmail.
Inbucket is an email testing service. It accepts messages for any email address and makes them available to view via a Web interface. It allows Web developers, software engineers, and system administrators to quickly see the emailed output of their applications. No per-account setup is required. Mailboxes are created on the fly as mail is received for them, and no password is required to browse the content of the mailboxes.