How/where do I find WebHost settings to choose the Remote Email server option

I've found this information: "When you use 'Contact us' forms or 'Webforms' from a website, the Submit option is typically used to send emails. These emails are triggered from your Website Hosting Provider (Web Host). In most cases, the website's domain name matches the domain name in the email address they are sent from. Ex: www.yourdomain.com/contact.html page will submit the details to contact@yourdomain.com.

In this case, the Web Host or email server which triggers an email wrongly assumes that the emails should be delivered locally because the domain name is the same."

It says to correct this I need to go to the WebHost settings and change to the "remote email server" option. Would that be somewhere in Homestead? It sounds like it would have to be, but I don't see where to find that.