Several days ago I found that in a certain environment JavaMail may throw an AuthenticationException even you have set right user/password. Maybe this will not happen in a different mail server, but I'm not sure. So I just write it down and hope this can help someone who encounters such a problem.
Firstly I'd like to say the code is complied to specifications. The snippet:
props = new Properties();
props.put( "mail.smtp.host", mailhost );
props.put( "mail.smtp.port", port );
props.put("mail.user", username);
props.put("mail.password", password);
props.put("mail.smtp.auth", "true");
javax.mail.Session session = javax.mail.Session.getInstance(props);
Message msg = new MimeMessage(session);
msg.setFrom( new InternetAddress( from ) ); // from is "user@localhost".
msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse( recipient, false ) );
msg.setSubject( subject );
msg.setContent(text, "text/html");
msg.setSentDate(new Date());
// send the thing off
Transport transport = null;
try {
PasswordAuthentication pa = new PasswordAuthentication((String)props.get("mail.user"),
(String)props.get("mail.password"));
transport = session.getTransport("smtp");
URLName urlname = transport.getURLName();
session.setPasswordAuthentication(urlname, pa);
if (!transport.isConnected()) {
transport.connect();
}
Transport.send(msg);
} catch (MessagingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
throw e;
} finally {
transport.close();
}
The code was tested ok in another program, and, use the same email server (Coremail). But whenever I debug this one, I got an AuthenticationException.
Nearly everything was the same to the another program, but of cause, actually not.
At last I opened the debug mode, like this:
javax.mail.Session session = javax.mail.Session.getInstance(props);
session.setDebug(true);
session.setDebugOut(System.out);
Then I found it out.
msg.setFrom( new InternetAddress( from ) ); // from is "user@localhost".
The mail server not only need a user account and password, but also the right msg.setFrom().
After I set "from" to my real email address regarding to the mail server, everything went right.
And the conclusion is, as I guess, that some mail server would only accept an account in its system to send a mail. I dont know if this rule is suitable to all mail servers, because I have no chance to try others.
By Feelyou, under CC License. Technorati 標簽:
JavaMail,
AuthenticationException