Gmail Notifier Pro can check multiple Gmail, Yahoo and Hotmail accounts for new mail and notify you from the system tray when new messages arrive. Each account can have it's own color scheme, making it easy to distinguish your accounts. You can also choose to limit monitoring to messages with a specific label and reply to messages without the need to open your browser. Other features include integration with Google contacts, support for Google calendar, RSS/Atom feeds, IMAP support, portable mode, and more.