The SMS Server Tools 3 is a SMS Gateway software which can send and
receive short messages through GSM modems and mobile phones.

You can send short messages by simply storing text files into a
special spool directory.  The program monitors this directory and
sends new files automatically.  It also stores received short messages
into another directory as text files.  Binary messages (including
Unicode text) are also supported, for example ring tone messages.
It's also possible to send a WAP Push message to the WAP / MMS
capable mobile phone.

The program can be run as a SMS daemon which can be started
automatically when the operating system starts.  High availability
can be ensured by using multiple GSM devices (currently up to 64,
but this limit is easily changeable).

Note: users should be added to dialout group to send/receive messages.