SMTP Authentication Support | PHPMailer ... which one is more secured and stable for Drupal 6.19

Hello all,

I am using linode.com hosting and this is why I need to have a way to send emails from my website.

I've searched and found these two modules which can do the job:-
1) SMTP Authentication Support.
2) PHPMailer.

.. but really do not know which one is more stable and more secured?

Please advise for your recommendations.

Thanks