AutoSender gives an error "[DataDirect][SequeLink JDBC Driver]TCP/IP error, connection refused." What's going on?

The error "SQLException "[DataDirect][SequeLink JDBC Driver]TCP/IP error, connection refused" usually means FM Server is not accepting the JDBC connection. There may be several reasons, usually independent of AutoSender:
Either JDBC sharing is not active for that particular file, or the xDBC user information is incorrect, or xDBC sharing is inactive on the server.

Try to "telnet [IP of your FileMaker Server] 2399" from Terminal (Mac) or from the command prompt (Windows) to see whether the connection isn't refused. You should get a message 'Connected to…'. If you don’t, then there is an issue with FMS accepting ODBC connections.