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问题:

I am doing a sendMail Servlet with JavaMail. I have javax.mail.AuthenticationFailedException on my output. Can anyone please help me out? Thanks.

sendMailServlet code:

try {
        String host = "smtp.gmail.com";
        String from = "my@gmail.com";
        String pass = "pass";
        Properties props = System.getProperties();
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.user", from);
        props.put("mail.smtp.password", pass);
        props.put("mail.smtp.port", "587");
        props.put("mail.smtp.auth", "true");
        props.put("mail.debug", "true");

        Session session = Session.getDefaultInstance(props, null);
        MimeMessage message = new MimeMessage(session);
        Address fromAddress = new InternetAddress(from);
        Address toAddress = new InternetAddress("test1@gmail.com");

        message.setFrom(fromAddress);
        message.setRecipient(Message.RecipientType.TO, toAddress);

        message.setSubject("Testing JavaMail");
        message.setText("Welcome to JavaMail");
        Transport transport = session.getTransport("smtp");
        transport.connect(host, from, pass);
        message.saveChanges();
        Transport.send(message);
        transport.close();

    }catch(Exception ex){

        out.println("<html><head></head><body>");
        out.println("ERROR: " + ex);
        out.println("</body></html>");
    }

Output on GlassFish 2.1:

DEBUG SMTP: trying to connect to host "smtp.gmail.com", port 587, isSSL false
220 mx.google.com ESMTP 36sm10907668yxh.13
DEBUG SMTP: connected to host "smtp.gmail.com", port: 587
EHLO platform-4cfaca
250-mx.google.com at your service, [203.126.159.130]
250-SIZE 35651584
250-8BITMIME
250-STARTTLS
250-ENHANCEDSTATUSCODES
250 PIPELINING
DEBUG SMTP: Found extension "SIZE", arg "35651584"
DEBUG SMTP: Found extension "8BITMIME", arg ""
DEBUG SMTP: Found extension "STARTTLS", arg ""
DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
DEBUG SMTP: Found extension "PIPELINING", arg ""
STARTTLS
220 2.0.0 Ready to start TLS
EHLO platform-4cfaca
250-mx.google.com at your service, [203.126.159.130]
250-SIZE 35651584
250-8BITMIME
250-AUTH LOGIN PLAIN
250-ENHANCEDSTATUSCODES
250 PIPELINING
DEBUG SMTP: Found extension "SIZE", arg "35651584"
DEBUG SMTP: Found extension "8BITMIME", arg ""
DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN"
DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
DEBUG SMTP: Found extension "PIPELINING", arg ""
DEBUG SMTP: Attempt to authenticate
AUTH LOGIN
334 VXNlcm5hbWU6
aWpveWNlbGVvbmdAZ21haWwuY29t
334 UGFzc3dvcmQ6
MTIzNDU2Nzhf
235 2.7.0 Accepted
DEBUG: getProvider() returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun Microsystems, Inc]
DEBUG SMTP: useEhlo true, useAuth true

回答1:

You need to implement a custom Authenticator

import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;


class GMailAuthenticator extends Authenticator {
     String user;
     String pw;
     public GMailAuthenticator (String username, String password)
     {
        super();
        this.user = username;
        this.pw = password;
     }
    public PasswordAuthentication getPasswordAuthentication()
    {
       return new PasswordAuthentication(user, pw);
    }
}

Now use it in the Session

Session session = Session.getInstance(props, new GMailAuthenticator(username, password));

Also check out the JavaMail FAQ

回答2:

Hello Everyone This error is from google security... This Can Be Resolved by Enabling Less Secure .

Go To This Link : "https://www.google.com/settings/security/lesssecureapps" and Make "TURN ON" then ur application runs For Sure.

回答3:

I was missing this authenticator object argument in the below line

Session session = Session.getInstance(props, new GMailAuthenticator(username, password));

This line solved my problem now I can send mail through my Java application. Rest of the code is simple just like above.

回答4:

The problem is, you are creating a transport object and using it's connect method to authenticate yourself. But then you use a static method to send the message which ignores authentication done by the object.

So, you should either use the sendMessage(message, message.getAllRecipients()) method on the object or use an authenticator as suggested by others to get authorize through the session.

Here's the Java Mail FAQ, you need to read.

回答5:

Just wanted to share with you:
I happened to get this error after changing Digital Ocean machine (IP address). Apparently Gmail recognized it as a hacking attack. After following their directions, and approving the new IP address the code is back and running.