550 Bad HELO - Host impersonating domain name Laravel

I'm trying to setup Laravel auth including the 'Password Reset' function. But I am stumbeling upon a error when I try to send the email. The error I get is:

Expected response code 250 but got code "550", with message "550 Bad HELO - Host impersonating domain name 

Im using Laravel 5.6 with Cloudflare. My hosting said that that might be the issue but I've already tried to disable all Cloudflare DNS functions inside the Cloudflare Dashboard, but that didnt work. I am sure I am using the correct mails settings since they work fine on my phone and any other devices. Also, I've tried switching ports and it doesnt matter if I fill in a valid port or not, it will keep giving me this error.

via Chebli Mohamed