[SOLVED] JavaMail Authentication Problem

[frost750]

Brand new to the JavaMail API. Using the following code to try and send a message from my Java desktop application:

String protocol = "smtp";

Properties props = new Properties();
props.put("mail.smtp.host", "smtp.*****.***");
props.put("mail.from", "*********@u.washington.edu");
props.put("mail." + protocol + ".auth", "true");
Session session = Session.getInstance(props, null);

try
{ MimeMessage msg = new MimeMessage(session);
msg.setFrom();
msg.setRecipients(Message.RecipientType.TO, "********@hotmail.com");
msg.setSubject("a test");
msg.setSentDate(new Date());
msg.setText("a test message\n");
Transport t = session.getTransport(protocol);

try
{ t.connect("*******", "*********");
t.sendMessage(msg, msg.getAllRecipients());
} finally { t.close(); }

} catch (MessagingException mex) { System.out.println("send failed, exception: " + mex); }

The usernames and passwords have been replaced with the ****. This question has probably been asked before but I cannot find a thread with search. The error i get is:

send failed, exception: javax.mail.SendFailedException: Invalid Addresses;
nested exception is: com.sun.mail.smtp.SMTPAddressFailedException: 530 5.7.1 Relaying denied. Proper authentication required.

When googling for a solution I find many having similar problems except that the error code they get is 550. I have tried several solutions that have worked for others but every single attempt gives me the 530. The username, password and mail server are all valid. Thanks for any suggestions.

[frost750]

Problem was solved by adding the following line of code.

props.put("mail.smtp.starttls.enable","true");