You need to tell it that you are using SSL:
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
In case you miss anything, here is working code:
String d_email = "[email protected]",
d_uname = "Name",
d_password = "urpassword",
d_host = "smtp.gmail.com",
d_port = "465",
m_to = "[email protected]",
m_subject = "Indoors Readable File: " + params[0].getName(),
m_text = "This message is from Indoor Positioning App. Required file(s) are attached.";
Properties props = new Properties();
props.put("mail.smtp.user", d_email);
props.put("mail.smtp.host", d_host);
props.put("mail.smtp.port", d_port);
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.debug", "true");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.socketFactory.port", d_port);
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
SMTPAuthenticator auth = new SMTPAuthenticator();
Session session = Session.getInstance(props, auth);
session.setDebug(true);
MimeMessage msg = new MimeMessage(session);
try {
msg.setSubject(m_subject);
msg.setFrom(new InternetAddress(d_email));
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(m_to));
Transport transport = session.getTransport("smtps");
transport.connect(d_host, Integer.valueOf(d_port), d_uname, d_password);
transport.sendMessage(msg, msg.getAllRecipients());
transport.close();
} catch (AddressException e) {
e.printStackTrace();
return false;
} catch (MessagingException e) {
e.printStackTrace();
return false;
}