WinLink
Winlink is an email system like Yahoo, Hotmail, and AOL. Winlink users can send messages to and receive messages from any other email address. Where Winlink differs is that Winlink allows amateur radio operators to reach the system over a VHF or HF amateur transceiver using a Windows-based program and a sound card interface or terminal node controller (TNC).
RMS Express is a Windows program which uses a sound card interface for HF, a Pactor-capable TNC for HF, or a packet TNC for VHF. Email gateways using the same sound card or TNC serve as connection points into the Winlink system. Using RMS Express, a ham can connect to a gateway to send and receive email messages.
RMS Express also provides a direct internet connection mode if the computer has an internet connection, and offers a peer to peer (station to station) capability over the sound card interface.
These modes of operation provide the ham with the ability to bring email to locations where no conventional connection exists, or where such a connection is temporarily unavailable.