The GeoMail application listens for incoming emails from your e-mail account. For each received e-mail, the originating senders IP-address is extracted and an external Web Service is used to resolve that IP-address into a Geographic location. This information is then used to display, in a Google Map, how geographically spread you e-mail correspondance is. GeoMail can, for example, be used by Open-Source projects to visualize how widespread its mailinglist subscribers are.