void form::on_pushButton_pressed()
{
        SmtpAuthData smtpAuthData;
        SmtpAuthData::Data data;
        // your email address
        data.email = "От кого";
        // login for your email account
        data.login = "Логин";
        // name which will be shown in From: line(optional)
        //data.name = QString::fromLocal8Bit("");
        // password for auth on email account
        data.password = "Пароль";
        // port for host 587 default
        //data.port = "";
        // ssl support
        //data.enableSsl = true;
        smtpAuthData.rewriteData(data);

        Letter letter(smtpAuthData);

        QString secondFile("");

        QStringList filesList;
        filesList << secondFile;


        QString receivers = QString::fromLocal8Bit("Кому");
        //QString blindCopyReceivers = "";
        // choice letter encoding
        //letter.set_encoding("");
        letter.set_receivers(receivers);
        //letter.set_blindCopyReceivers(blindCopyReceivers);
        //letter.set_subject(QString::fromLocal8Bit(""));
        //letter.set_attachement(filesList);
        letter.set_text(QString::fromLocal8Bit("Проверка"));

        // send letter
        letter.send();
}

Email at ->  "От кого" 
Ready read ->  31 
Block size ->  31 
Server request ->  "220 smtp9.mail.ru ESMTP ready
" 
Ready read ->  88 
Block size ->  88 
Server request ->  "250 STARTTLS
" 
Ready read ->  18 
Block size ->  18 
Server request ->  "334 VXNlcm5hbWU6
" 
Ready read ->  18 
Block size ->  18 
Server request ->  "334 UGFzc3dvcmQ6
" 
Ready read ->  30 
Block size ->  30 
391 
Server request ->  "235 Authentication succeeded
" 
Ready read ->  8 
Block size ->  8 
Emails to ->  "Кому" 
Server request ->  "250 OK
" 
Ready read ->  14 
Block size ->  8 
Server request ->  "250 Accepted
" 
Ready read ->  56 
Block size ->  56 
Server request ->  "354 Enter message, ending with "." on a line by itself
" 
Ready read ->  28 
Block size ->  28 
Server request ->  "250 OK id=1SYEZa-0001Ad-Sr
" 

Email at ->  "От кого"