GmailAssistant is a notifier for multiple Gmail and Google Apps e-mail accounts. GmailAssistant accesses your accounts securely using IMAP over SSL. Choose from different notification options (unread mails in inbox only, all mails, or with specified labels) and alert methods (popup message, chime, blink keyboard LED). Free and open source software written in Java.
Version 2 includes IMAP IDLE support, ability to minimize on startup, and automatic update check.