无法在我的项目中发送邮件

Question

我无法在我的项目中发送邮件。错误代码是：

java.lang.RuntimeException: javax.mail.SendFailedException: Sending failed;
  nested exception is:
    class javax.mail.AuthenticationFailedException
    Servlet.MailServlet.service(MailServlet.java:57)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

javax.mail.SendFailedException: Sending failed;
  nested exception is:
    class javax.mail.AuthenticationFailedException
    javax.mail.Transport.send0(Transport.java:218)
    javax.mail.Transport.send(Transport.java:80)
    Servlet.MailServlet.service(MailServlet.java:53)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:722)