Why javax.mail port changed from 2525 to 25

Question

I use mandrill to send mails. Port is set to 2525

props = new Properties();
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.starttls.enable", "true");
//props.put("mail.smtp.**ssl.enable", "true");
//props.put("mail.smtp.**ssl.required", "true");
props.put("mail.smtp.host", settings.host);
props.put("mail.smtp.port", settings.port);

And I am sure that all setting are valid.

Then I set authenticator

authenticator = new javax.mail.Authenticator() {
    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(settings.username, settings.password);
    }
};

And sfter that send mail

Session session = Session.getInstance(props, authenticator);
session.setDebug(true);
try {
    Message message = mail.getMessage(session); 
    Transport.send(message);
    System.out.println("Done");
    return true;
} catch (MessagingException e) {
    e.printStackTrace(System.err);
    return false;
}

Debug says that I send mail on 25th port

DEBUG: setDebug: JavaMail version 1.4ea
DEBUG: getProvider() returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.s
mtp.SMTPTransport,Sun Microsystems, Inc]
DEBUG SMTP: useEhlo true, useAuth true
DEBUG SMTP: useEhlo true, useAuth true
DEBUG SMTP: trying to connect to host "smtp.mandrillapp.com", port 25, isSSL fal
se
220 smtp.mandrillapp.com ESMTP
DEBUG SMTP: connected to host "smtp.mandrillapp.com", port: 25

I tried to create "smtps" transport, but that didn't help. Mandrill says that I can use port 2525 (or 587, and other). I also send on port 2525 using postfix from linux server with same credentials.

Answer 1

The error is quite stupid)

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

in this line port is an int value, when I changed port field to String it started working.