gistfile1.txt

public interface AsyncCommandHandler extends AsyncProtocolHandler {

    public void onCommand(SMTPSession session, SMTPRequest request, SMTPResponseCallback callback);
}

public class AsyncCommandHandlerAdapter implements AsyncCommandHandler {

    public AsyncCommandHandlerAdapter(CommandHandler handler) {
        this.handler = handler;
    }
    public void onCommand(SMTPSession session, SMTPRequest request, SMTPRequestCallback callback) {
        SMTPResponse response handler.onCommand(session, request);
        callback.onResponse(session,response);
    }
}