testmail is a Perl script that checks email availability at the POP3 server (including SSL), filters it according to the defined rules, and (depending on the selected method) gets the messages to the local mailbox and/or removes them from the server. It uses Perl Mail-POP3Client to establish POP3 connections, IO-Socket-SSL and Net-SSLeay modules for SSL connections, as well as MIME-tools module for decoding MIME encoded email fields.
IGSuite is a Web-based groupware collaboration suite. It gives you a "box" of applications that includes wiki, email, documents, calendar, tasks, fax, contacts, notes, links, and more. The power of collaboration comes in when these individual suite components are shared and used within a group. It strives to provide location independence, platform independence, machine independence, and browser independence.
phlyMail is a groupware, webmailer, and PIM. It offers unlimited nested groups, unlimited POP3/IMAP profiles, quotas, an integrated address book, a calendar with multiple reminders and event repetitions, a file manager with an integrated WebDAV server, the ability to send faxes, SMS support (which lets you send SMS, get reminded of events via SMS, and get email notification via SMS), a bookmark manager, themes, and multilingual support. It uses either sendmail or SMTP to send email, and can handle MIME and SSL connections. Support for IDN (Internationalized Domain Names) is included. Through its modular design, it's easy to add completely new features as modules, which can be plugged into the system.
GroupOffice is a groupware suite that takes your office online, implementing online collaboration and CRM. It allows you to share projects, calendars, files and email online with co-workers and clients. It is easy to use and fully customizable. It also features synchronization with PDAs and Outlook.
Hastymail is a full featured IMAP/SMTP client written in PHP. The goal is a full featured yet lightweight Web mail client. After a complete review and rewrite, it provides many improvements over the original code including optional AJAX functionality, improved code organization, a plugin API, CSS and PHP template themes, and much more.
Mailbox Sweeper lets you delete email messages in your mailbox without downloading them. You can log into your mailbox, preview the Subject lines of the messages stored there, then delete multiple selected email messages, or all of them at once. It's useful for cleaning spam-ridden mailboxes, or to delete a big attachment without having to download it.