QByteArray data = ui->send->text().toAscii() + "\r\n";
imapSocket->write(data);

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    imapSocket = new QTcpSocket(this);
    imapSocket->connectToHost(QHostAddress("127.0.0.1"), 143);
    connect(imapSocket, SIGNAL(readyRead()), SLOT(readMessage()));

}

MainWindow::~MainWindow()
{
    delete ui;
    imapSocket->close();
}

void MainWindow::on_ok_clicked()
{
    qDebug() << imapSocket->state();
    if(ui->send->text().isEmpty()) return;
    QByteArray data = ui->send->text().toAscii();
    imapSocket->write(data);
    ui->send->clear();
}


void MainWindow::readMessage()
{
    QByteArray datagram;
    datagram = imapSocket->readAll();
    QString ans(datagram);
    ui->answer->append(ans);
}