使用 Javamail 连接到 Gmail smtp 服务器会忽略指定端口并尝试使用 25

It appears to be trying to use port 25 even though I've specified that it should use port 587. Does anyone know what could be causing this problem, I've used telnet to connect to the smtp server on port 587, and thunderbird uses port 587 with STARTTLS security and is able to successfully send mail using the smtp server. This tells me that it is not a blocked port or connectivity issue. Here is the code I'm using to try and send the email:

import javax.mail.*
import javax.mail.internet.*

private class SMTPAuthenticator extends Authenticator
{
    public PasswordAuthentication getPasswordAuthentication()
    {
        return new PasswordAuthentication('email@gmail.com', 'password');
    }
}

def  d_email = "email@gmail.com",
        d_password = "password",
        d_host = "smtp.gmail.com",
        d_port  = "587", //465,587
        m_to = "email@gmail.com",
        m_subject = "Testing",
        m_text = "This is a test."

def props = new Properties()
props.put("mail.smtp.user", d_email)
props.put("mail.smtp.host", d_host)
props.put("mail.smtp.port", d_port)
props.put("mail.smtp.starttls.enable","true")
props.put("mail.smtp.debug", "true");
props.put("mail.smtp.auth", "true")
props.put("mail.smtp.socketFactory.port", d_port)
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory")
props.put("mail.smtp.socketFactory.fallback", "false")

def auth = new SMTPAuthenticator()
def session = Session.getInstance(props, auth)
session.setDebug(true);

def msg = new MimeMessage(session)
msg.setText(m_text)
msg.setSubject(m_subject)
msg.setFrom(new InternetAddress(d_email))
msg.addRecipient(Message.RecipientType.TO, new InternetAddress(m_to))
Transport.send(msg)

任何帮助将不胜感激.提前致谢！

Transport transport = session.getTransport("smtps");
transport.connect (smtp_host, smtp_port, smtp_username, smtp_password);
transport.sendMessage(msg, msg.getAllRecipients());
transport.close();