Change mail exchange option to remote mail exchanger?

I'm having trouble with zoho mail. They said that the mail exchange option needs to be changed to Remote Mail exchanger or Deliver emails to MX records. I've been all over my Linode settings and can't find this anywhere.

The problem is that I'm not getting emails through contact forms. So for example, the contact forms on my websites, or if I try to use an email verification on a third party site using one of the emails associated with one of my domains.