Android : Javamail Send email by using different stmp

I try to send email using javamail by using different stmp & port number

I use this code:

public class Custommail extends javax.mail.Authenticator { 
    private String _user; 
      private String _pass; 

      private String[] _to; 
      private String _from; 

      private String _port; 
      private String _host; 

      private String _subject; 
      private String _body; 

      private Multipart _multipart; 

      static {   
          Security.addProvider(new JSSEProvider());   
      }

      public void setTo(String[] toArr) {
          this._to = toArr;
          }

          public void setFrom(String string) {
          this._from = string;
          }

          public void setSubject(String string) {
          this._subject = string;
          }
      public Hotmail() {
        _host = ""; // default smtp server 
        _port = ""; // default smtp port 
        _user = ""; // username 
        _pass = ""; // password 
        _from = ""; // email sent from 
        _subject = ""; // email subject 
        _body = ""; // email body 

        _multipart = new MimeMultipart(); 

        // There is something wrong with MailCap, javamail can not find a handler for the multipart/mixed part, so this bit needs to be added. 
        MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap(); 
        mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html"); 
        mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml"); 
        mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain"); 
        mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed"); 
        mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822"); 
        CommandMap.setDefaultCommandMap(mc);  
      } 

      public Hotmail(String user, String pass, String host, String port) {
            this(); 

            _host = host;
            _port = port;
            _user = user;
            _pass = pass;
      } 

      public boolean send() throws Exception { 
        Properties props = _setProperties(); 

        if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) { 
          Session session = Session.getInstance(props, this); 

          MimeMessage msg = new MimeMessage(session); 

          msg.setFrom(new InternetAddress(_from)); 

          InternetAddress[] addressTo = new InternetAddress[_to.length]; 
          for (int i = 0; i < _to.length; i++) { 
            addressTo[i] = new InternetAddress(_to[i]); 
          } 
            msg.setRecipients(MimeMessage.RecipientType.TO, addressTo); 

          msg.setSubject(_subject); 
          msg.setSentDate(new Date()); 
          // setup message body 
          BodyPart messageBodyPart = new MimeBodyPart(); 
          messageBodyPart.setText(_body); 
          _multipart.addBodyPart(messageBodyPart); 

          // Put parts in message 
          msg.setContent(_multipart); 

          // send email 
          Transport.send(msg); 

          return true; 
        } else { 
          return false; 
        } 
      } 

      public void addAttachment(String filename) throws Exception { 
        BodyPart messageBodyPart = new MimeBodyPart(); 
        DataSource source = new FileDataSource(filename); 
        messageBodyPart.setDataHandler(new DataHandler(source)); 
        messageBodyPart.setFileName(filename); 

        _multipart.addBodyPart(messageBodyPart); 
      } 

      @Override 
      public PasswordAuthentication getPasswordAuthentication() { 
        return new PasswordAuthentication(_user, _pass); 
      } 

      private Properties _setProperties() { 
          Properties props = new Properties(); 

          props.put("mail.smtp.user",_user); 
          props.put("mail.smtp.password", _pass);
          props.put("mail.smtp.host", _host); 
          props.put("mail.smtp.port", _port);
          props.put("mail.smtp.auth", "true"); 
          props.put("mail.smtp.starttls.enable","true"); 
          props.put("mail.smtp.EnableSSL.enable","true");


        return props; 
      } 

      // the getters and setters 
      public String getBody() { 
        return _body; 
      } 

      public void setBody(String _body) { 
        this._body = _body; 
      } 

      // more of the getters and setters ….. 
    }

And When Send Email:

CustomMail m = new CustomMail("email","pass","stmp","port number");

but the app get error as:

"com.sun.mail.smtp.SMTPSendFailedException: 550-Requested action not taken: mailbox unavailable 550 Sender address is not allowed."