WinLink 2000 and APRS

WinLink 2000 is generally designed for HF communication, but they have a nice APRS gateway as well, enabling short messages to be sent to and from email accounts from APRS users.

Amateur radio is a radio service in which people are allowed and encouraged to build their own radios, antennas, and so forth. It can be used to communicate all around the globe without any intervening infrastructure such as satellites or cables.