IBM's Lotus Notes has the ability to display a popup message when you receive new email. This method only works for email hosted on a Domino Server and uses AMAP Online Internet Mail. If you are not sure whether your email meets this criteria, check with your organization's system administrator.
In Lotus Notes, select "Preferences" from the File menu.
Expand the Mail option by clicking the "+" next to "Mail."
Select "Check for New Mail Every X Minutes." Set the interval, in minutes, for Notes to check for new mail.
Click "Display a Popup Alert" and click "OK."