JavaMail SMTP credentials verification, without actually sending an email.
- by DarK
Hi,
Is there a way to check user SMTP server credentials without sending email, or connecting to POP/IMAP.
Some code I tried to write, fails at it.
Can you find what is missing there.
Don't worry about Email / password. I know it's there.
NOTE : If you are trying out the code. The case 1 should pass when supplying the correct credentials.
If it fails, then someone changed the password. You should use some other email address.
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
public class EmailTest {
public static void main(String[] args) {
EmailHelper eh = new EmailHelper();
/* GMail Setting for SMTP using STARTTLS */
String name = "AAA";
String email = "[email protected]";
String smtpHost = "smtp.gmail.com";
String serverPort = "587";
String requireAuth = "true";
String dontuseAuth = "false";
String userName = email; // same as username for GMAIL
String password = "zaq12wsx";
String incorrectPassword = "someRandomPassword";
String enableSTARTTLS = "true";
String dontenableSTARTTLS = "false";
try {
/* only valid case */
eh.sendMail(name, email, smtpHost, serverPort, requireAuth,
userName, password, enableSTARTTLS);
System.out.println("Case 1 Passed");
/* should fail since starttls is required for GMAIL. */
eh.sendMail(name, email, smtpHost, serverPort, requireAuth,
userName, password, dontenableSTARTTLS);
System.out.println("Case 2 Passed");
/* should fail since GMAIL requires authentication */
eh.sendMail(name, email, smtpHost, serverPort, dontuseAuth, "", "",
dontenableSTARTTLS);
System.out.println("Case 3 Passed");
/* should fail. password is incorrect and starttls is not enabled */
eh.sendMail(name, email, smtpHost, serverPort, requireAuth,
userName, incorrectPassword, dontenableSTARTTLS);
System.out.println("Case 4 Passed");
} catch (MessagingException e) {
e.printStackTrace();
}
}
}
class EmailHelper {
private Properties properties = null;
private Authenticator authenticator = null;
private Session session = null;
public void sendMail(String name, String email, String smtpHost,
String serverPort, String requireAuth, String userName,
String password, String enableSTARTTLS) throws MessagingException {
properties = System.getProperties();
properties.put("mail.smtp.host", smtpHost);
properties.put("mail.smtp.port", serverPort);
properties.put("mail.smtp.starttls.enable", enableSTARTTLS);
properties.put("mail.smtp.auth", requireAuth);
properties.put("mail.smtp.timeout", 20000);
authenticator = new SMTPAuthenticator(userName, password);
session = Session.getInstance(properties, authenticator);
// session.setDebug(true);
Transport tr = session.getTransport("smtp");
tr.connect();
/*
* do I need more than just connect? Since when i try to send email with
* incorrect credentials it fails to do so. But I want to check
* credentials without sending an email. Assume that POP3/IMAP username
* is not same as the SMTP username, since that might be one of the
* cases
*/
}
}
class SMTPAuthenticator extends Authenticator {
private String userName = null;
private String password = null;
public SMTPAuthenticator(String userName, String password) {
this.userName = userName;
this.password = password;
}
@Override
public PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(userName, password);
}
}
