We're using Windows 2003 Server, IIS 6.0, PHP 5.0, and MySQL 4.1 on the server and Windows XP Pro on the client PCs. Managers want to develop a web-based email client for agents to use to email them directly to their MS Outlook inbox and to be able to send replies from it back to their web-based account. Emailing outside the intranet should be forbidden. I can make my own web-based client to achieve the above request but wanted to know if there's some free library or something which i can make slight modifications to, to achieve the above. Even if its a standard Windows application i'd consider it. Anything to save me from having to develop the email client from scratch.
Thanks for any pointers. Just in case I do have access to PHP and MySql.