The SMS Server Tools 3 is a SMS gateway that can send and receive short messages through GSM modems and mobile phones. Messages are sent by simply storing text files into a special spool directory. It also stores received messages into another directory as text files. Binary messages including Unicode text and ring tones are also supported, and it is possible to send WAP Push and system messages. The program can run scripts after events like the reception of a message, successful sending, and when the program detects a problem.