All Email accounts checker in One

Pop Peeper is one of the most powerful Email checkers I've come across. It's also FREE to use.
This program will check your POP3, IMAP (including AOL, AIM, Netscape, FastMail, etc), SMTP, GMail, Hotmail\MSN\LiveMail, Yahoo, Mail.com, MyWay, Excite, Lycos.com, RediffMail, Juno, NetZero accounts. You can also send out Emails straight from POP Peeper, use inbuilt Address Book, Send, Save & Open any attachments, choose Plain or HTML email format.
A very nice feature is Email Notification options, check them out
* Sound notifications: single sound for any new mail, or a customized sound for each account
* Tray icon notification, with options to display the color and number of new messages for each account
* Flashing scroll lock LED
* Windows popup alert indicating which account(s) received new email

I started using it about a month ago and really happy with it, since I don't have to login into any of my email accounts any more, they all come to me now :)
Highly advisable, time saving program!