A perl-based feature-rich web email system supporting access via web, WAP, POP3 or IMAP. Fully customizable, with web-admin, scheduler, migration scripts and Unix/Windows technical support. [Commercial]
Web IMAP NNTP Gateway, an open source Apache/mod_perl based system which allows users to access email held on an IMAP server via any web browser. [Free]
A web-based software module for online mail management. It helps you check and organize your Internet mail through your Web Browser, from an IIS server. [Commercial]