Will PHP Mailer Work in WOrdPResS?

Hey I feel like I've been googling this for hours now. So I'm trying to find the best practice in sending an emails using PHP Mailer using Gmail STMP in WordPress. I seem to run across a ton of different ways to do this but non have been able to convince me that this is the true way to do this. I'm trying to learn this the right ways so I can hook up this service for potential clients. I don't want to be liable for sensitive client information that gets sent thru email and is hacked or whatever can happen online. If one of the Treehouse teacher/moderators can explain how to do this/how it works, then I will have faith in what I am doing. I will be posting this in the PHP/WordPress section of the forum so this could reach ppl in both subjects. Here are some links I've already checked out but don't know if they are doing this in the best possible way:

http://brandintellect.in/send-email-gmail-smtp-wordpress-wp_mail/ http://www.butlerblog.com/2012/09/23/testing-the-wp_mail-function/ https://www.saotn.org/send-authenticated-smtp-email-over-tls-wordpress/ http://php.codeindepth.com/php-sending-mail/ https://wordpress.org/support/topic/phpmailer-1 http://stackoverflow.com/questions/16048347/send-email-using-gmail-smtp-server-through-php-mailer

Thanks!