From: Clay Witt on
Several people, including myself, have experienced this issue recently. If
1and1 is your ISP, here is the solution.

Go to the 1&1 EasyLogin tray utility. Right click it and then left click on
"Application settings."

In the box that opens go down to "Desktop Alert" and left click the settings
button.

Remove the check from the box to the left of "Activate desktop alert for new
emails."

Left click OK, the OK again to close.

Your problem should then disappear. It did for me.

url:http://www.ureader.com/msg/107582833.aspx