smtp java,JavaMail smtp属性（适用于STARTTLS）

JavaMail specifies a bunch of properties that can be set to configure an SMTP connection. To use STARTTLS it is necessary to set the following property

mail.smtp.starttls.enable=true

Where do I specify the username/password to use the smtp service? Is it enough to specify the:

mail.smtp.user=me

mail.smtp.password=secret

Or do I have to explicitely login using the:

transport.connect(server, userName, password)

Yes, I already tried to do this and it seems that it is necessary to connect using transport.connect(..). But if yes, what are the mail.smtp.user & pass properties for? Are they not enough to use smtp with starttls?

解决方案

Here is my sendEmail method which is using GMail smtp (JavaMail) with STARTTLS

public void sendEmail(String body, String subject, String recipient) throws MessagingException,