public async Task            QuitTest()
        {
            using (var connection = new SMTPConnection()) {
                connection.RemoteEndPoint = _remoteEndPoint;
                connection.ConnectTimeout = 1000;
                await connection.OpenAsync(CancellationToken.None);

                await connection.QUIT_Async(CancellationToken.None);
            }
        }
        public async Task            SendTest()
        {
            using (var timer = new CancellationTokenSource(30000)) {
                using (var connection = new SMTPConnection()) {
                    connection.RemoteEndPoint = _remoteEndPoint;
                    connection.ConnectTimeout = 5000;
                    connection.Timeout        = 5000;
                    await connection.OpenAsync(timer.Token);

                    await connection.MAIL_FROM_Async("*****@*****.**", timer.Token);

                    await connection.RCPT_TO_Async("*****@*****.**", timer.Token);

                    await connection.DATA_Async("Description: Just a test\r\n" +
                                                "\r\n" +
                                                "Test from Jannesen.Protocol.SMTP.UnitTest",
                                                timer.Token);

                    await connection.QUIT_Async(timer.Token);
                }
            }
        }