Simple and effective, EZ Checker 2.5 is a nice program that checks for new email on different email account types and protocols:
New features in Ez Checker 2.5:
New Messages Window will appear each time a new message arrives. By using this feature, you can access each account independently.
Sound alerts. For each account you can choose a sound file to be played when new mail arrives (WAV files).
New and improved Help screen.
You can add an unlimited number of email accounts, and can you set the time interval individually for each one.
EZ Checker will alert you each time you will get new mail in the configured accounts by blinking the tray icon, and can perform different actions on click, after opening the "New Messages" window and after you select one of the accounts:
Opens your default mail client and lets you read your new arrived email
Opens your default web browser and logs you on (for Yahoo, Hotmail and Organizer)
Supported platforms: Windows 98, Windows ME, Windows 2000, Windows XP.