Context mainContext;

String title;
String text;
String text1;
String from;
String where;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity);

    mainContext = this;

    Button ibut = (Button) findViewById(R.id.button1);
    ibut.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            sender_mail_async async_sending = new sender_mail_async();
            async_sending.execute();
        }
    });
}

private class sender_mail_async extends AsyncTask<Object, String, Boolean> {
    ProgressDialog WaitingDialog;

    @Override
    protected void onPreExecute() {
        WaitingDialog = ProgressDialog.show(ExtendedMail.this, "Отправляем письмо...", true);
    }

    @Override
    protected void onPostExecute(Boolean result) {
        WaitingDialog.dismiss();
        Toast.makeText(mainContext, "Отправка завершена!!!", Toast.LENGTH_LONG).show();
        ((Activity)mainContext).finish();
    }

    @Override
    protected Boolean doInBackground(Object... params) {

        try {
            title = ((EditText)findViewById(R.id.editText1)).getText().toString();
            text = ((EditText)findViewById(R.id.editText2)).getText().toString();
            text1 = ((EditText)findViewById(R.id.editText3)).getText().toString();

            from = "mymail@yandex.ru";
            where = "myappmail@yandex.ru";

            MailSenderClass sender = new MailSenderClass("mymail@yandex.ru", "******");

            sender.sendMail(title, text, text1, from, where);
        } catch (Exception e) {
            Toast.makeText(mainContext, "Ошибка отправки сообщения!", Toast.LENGTH_SHORT).show();
        }

        return false;
    }
}

private String mailhost = "smtp.yandex.ru";
private String user;
private String password;
private Session session;

private Multipart _multipart;

static {
    Security.addProvider(new com.exampl1.projectisreal.JSSEProvider());
}

public MailSenderClass(String user, String password) {
    this.user = user;
    this.password = password;

    _multipart = new MimeMultipart();

    Properties props = new Properties();
    props.setProperty("mail.transport.protocol", "smtp");
    props.setProperty("mail.host", mailhost);
    props.put("mail.smtp.auth", "true");
    props.put("mail.smtp.port", "465");
    props.put("mail.smtp.socketFactory.port", "465");
    props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
    props.put("mail.smtp.socketFactory.fallback", "false");
    props.setProperty("mail.smtp.quitwait", "false");

    session = Session.getDefaultInstance(props, this);
}

protected PasswordAuthentication getPasswordAuthentication() {
    return new PasswordAuthentication(user, password);
}

public synchronized void sendMail(String subject, String body, String sender, String recipients, String filename) throws Exception {
    try {
        MimeMessage message = new MimeMessage(session);


        message.setSender(new InternetAddress(sender));

        message.setSubject(subject);

        if (recipients.indexOf(',') > 0)
            message.setRecipients(Message.RecipientType.TO,
                    InternetAddress.parse(recipients));
        else
            message.setRecipient(Message.RecipientType.TO,
                    new InternetAddress(recipients));


        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText(body);
        _multipart.addBodyPart(messageBodyPart);


        if (!filename.equalsIgnoreCase("")) {
            BodyPart attachBodyPart = new MimeBodyPart();
            DataSource source = new FileDataSource(filename);
            attachBodyPart.setDataHandler(new DataHandler(source));
            attachBodyPart.setFileName(filename);

            _multipart.addBodyPart(attachBodyPart);
        }

        message.setContent(_multipart);

        Transport.send(message);
    } catch (Exception e) {
        Log.e("sendMail","Ошибка отправки! ");
    }
}