Android verify email credentials

Question

I tried both answers from here: Validate smtp server credentials using java without actually sending mail without correct results.

The answers work for gmail authentication, but I'd like to be able to cover any SMTP host. I am testing using smtp.1and1.com. Whenever I give incorrect credentials (with both answers above) I still get a "success" message.

I'd like to have this formatted as the second answer, here's the code I'm using:

settings_email_test.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        String server = String.valueOf(settings_email_server_inp.getText());
        int port = Integer.parseInt(settings_email_port_inp.getText().toString());
        String username = String.valueOf(settings_email_username_inp.getText());
        String password = String.valueOf(settings_email_password_inp.getText());
        boolean auth = true;
        String security = "SSL";
        if(confirmSMTP(server, port, username, password, auth, security)){
            Toast.makeText(getApplicationContext(), "success", Toast.LENGTH_LONG).show();
        }
    }
});

with this method:

public boolean confirmSMTP(String host, int port, String username, String password, boolean auth, String enctype) {
    boolean result = false;
    try {
        Properties props = new Properties();
        if (auth) {
            props.setProperty("mail.smtp.auth", "true");
        } else {
            props.setProperty("mail.smtp.auth", "false");
        }
        if (enctype.endsWith("TLS")) {
            props.setProperty("mail.smtp.starttls.enable", "true");
        } else if (enctype.endsWith("SSL")) {
            props.setProperty("mail.smtp.startssl.enable", "true");
        }
        Session session = Session.getInstance(props, null);
        Transport transport = session.getTransport("smtp");
        transport.connect(host, port, username, password);
        transport.close();
        result = true;

    } catch(AuthenticationFailedException e) {
        Toast.makeText(getApplicationContext(), "SMTP: Authentication Failed", Toast.LENGTH_LONG).show();
    } catch(MessagingException e) {
        Toast.makeText(getApplicationContext(), "SMTP: Messaging Exception Occurred", Toast.LENGTH_LONG).show();
    } catch (Exception e) {
        Toast.makeText(getApplicationContext(), "SMTP: Unknown Exception", Toast.LENGTH_LONG).show();
    }

    return result;
}

Notice: I changed the code a bit from the one in the answer, just to make the port an int and the auth a boolean to begin with. Either way, I get a success message an no error messages when I use Incorrect Credentials. Though if I were to use gmail, everything works well.

What do I need to do to make this work for any SMTP host?

score 0 · Answer 1 · answered Feb 10 '16 at 21:20

The answers given in the link I posted both work - my problem was that my app was caching the information and I ran a "test" with Correct credentials first. Since those credentials were positive and the app cached those credentials, it kept writing success.

I cleared my cache on destroy of the app and those credentials were cleared with it. I am now able to get the correct interaction.

Android verify email credentials

1 Answers1