PHP mail() and SMTP Authentication ?

Hi all, I'm working on a server and want to send out mail either from a form to email or get email address from database then send I'm using PHP mail() currently the mail send out fine with simple PHP mail() ... but do I need to us PHP mail() and some kind of SMTP Authentication to lock it down? PHPMailer... or some better way? do I need to install something like this on the server? https://github.com/PHPMailer/PHPMailer If so what's best with PHP mail() ? or is there some more modern way to lock it down... -- Thanks, Dave - DealTek dealtek@gmail.com [db-15]