No, you can use EITHER JavaMail OR do a "Runtime.exec ("mail ...");". Your choice
JavaMail is just an API - you need a real "mail agent" for it to talk to.
Here's a good link:
1. Set up a GMail account (for testing purposes)
2. Write the JavaMail "hello world" in the link above
3. Use these GMail SMTP parameters:
4. Once your test case works, apply it to your actual app.
'Hope that helps