Java Mailing Logic: Could not convert socket to TLS

Question

In one application, I implemented mail sending logic using java. I used smtp.gmail.com over 587 port with a valid gmail id and password. In development environment everything is working fine. But in production environment I need to use a different mailing server say smtp.xyz.in over port 25 with a valid email id and password on that domain.

When I continue with SSL enable with following code:

I am getting an error

Could not convert socket to TLS

SunCertPathBuilderException: Unable To Find Valid Certification Path To Requested Target

=======================================================

final ResourceBundle rsbd=ResourceBundle.getBundle("main/ResourceBundle/Dyna");

        // -- Attaching to default Session, or we could start a new one                                            

                    props.put("mail.smtp.host", smtpServer);

                props.put("mail.smtp.auth", "true");

                props.put("mail.debug", "true");

            props.put("mail.smtp.port", port); 

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

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

  Session session =Session.getInstance(props, new Authenticator() {protected PasswordAuthentication getPasswordAuthentication() {return new PasswordAuthentication(admin_mail, admin_password);}});

         // -- Create a new message --
      Message msg = new MimeMessage(session);

     // -- Set the FROM and TO fields --
      msg.setFrom(new InternetAddress(from));

      msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(email, false));

      msg.setSubject(subject);
      msg.setText(emailContent);

      // -- Set some other header information --
      msg.setHeader("X-Mailer", "LOTONtechEmail");
      msg.setSentDate(new Date());

        // -- Send the message --
        Transport.send(msg);

When I am removing EnableSSL and trying by adding the following code:

(getting javax.mail.AuthenticationFailedException:535 5.7.3 Authentication unsuccessful)

==========================================================================

props.put("mail.smtp.socketFactory.port","25");

  props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

  props.put("mail.smtp.socketFactory.fallback", "true");


  MailSSLSocketFactory sf=new MailSSLSocketFactory();

  sf.setTrustAllHosts(true);

  props.put("mail.smtp.ssl.socketFactory", sf);

By googling enough in last 3 days, I understand that I need to configure for trusted certificate like given here.

But I want to continue without encryption and without mugging to enable SSL. Is there a way to send emails by java programs through our own domain without enabling SSL. Any help will be appreciated.

Answer 1

Whether SSL/TLS is required or not is controlled by your mail server. If it requires it, you have to use it.

You can set the mail.smtp.ssl.trust property to ignore the certificate issue, or you can fix it as described in the JavaMail FAQ.

Answer 2

If you are using

        props.put("mail.smtp.socketFactory.class",
            "javax.net.ssl.SSLSocketFactory");

Please remove this snippet to avoid SSL Configuration from SMTP server.

Answer 3

I've found that we have to set the correct TLS version also, otherwise we may get the same error. Below property settings helped to solve the issue.

<props>
    <prop key="mail.smtp.auth">true</prop>
    <prop key="mail.smtp.starttls.enable">true</prop>
    <prop key="mail.smtp.ssl.protocols">TLSv1.2</prop>
    <prop key="mail.smtp.ssl.trust">mail.XyZ.com</prop>
</props>

Answer 4

Usually, all you need to specify is the your SMTP server host, port and whether your SMTP server requires authentication when sending emails or not and if the communication with the SMTP server should be secured over SSL/TLS. You need to specify the corresponding properties correctly and thats it.

But, the above parameters are dictated by the SMTP server. The server decides whether it should accept only secured connections; and whether it should use SSL or more secure TLS and it would be either of them or both. Also, some SMTP servers do need senders authentication when sending emails while some don't. So, you need to check the documentation of the SMTP server you are to use to configure the parameters correctly. Refer here for a working example that uses Gmail to send emails

Answer 5

Hey Deactivate your antivirus it's working for me.

I deactivate only SMTP outbound in antivirus

Answer 6

This error could occur if you use an old JavaMail lib (mail.jar or javax.mail.jar). Download the newest version from here: https://javaee.github.io/javamail/