Error when add .jar file in Classpath
<p>Hi.<br>
I created a project which can send email using JavaMail. But when I add the .jar file in my classpath, I get the following error message. I don't know which error is this. Because it only show the "your project contain error" message.</p>

<p>Please provide me some answer.<br>
Thanks in Advance.  </p>
