@sterndata. Thank you very much for your response. It took me a while to setup, but one of my sites is now using the WP Mail SMTP plugin along with Ninja Forms. I uninstalled mailutils and postfix to prove that in fact that it is working. I had to edit my wp-config.php file, but now I can finally send mail out without it going to spam. The mail is actually being sent out from my mail provider which is defined from my MX records. So, to re-iterate, I can have users send mail to me, and have WordPress send special messages to me on my VPS, all without the email being rejected or going to spam.
Anyway, thank you very much for your recommendation. You saved me countless hours of having to figure out postfix etc.
