POP Peeper:
http://download.com.com/3000-2369-10111902.html
From the developer: "POP Peeper is a simple-to-use email notification program. New email is signalled to the user through audible and\or visual alerts. Email can be viewed and deleted right within the program; and by incorporating HTML, you will see the email just as you would through your regular email client. Context-sensitive help makes the already intuitive interface even easier to control. And if you are already using Outlook Express, Eudora, or Netscape as your email client, you can be up and running with all your accounts in a matter of seconds, thanks to a new Account Creation wizard.
"Some of the new version 2.1 features include: Hotmail support, a visual desktop notifier, the option to play a different sound for each account, ability to save\open file attachments, and the new Auto-Create Account wizard."