Funny how some admins get their website on shared hosting, put it behind Cloudflare, but leave MX hostname exposed directly.
Every folk who has dealt with hosting control panels knows that 99% of such domains will have both e-mail and web server on the same host 
It is easier to run e-mail servers with control panels on each node than build e-mail cluster separate from web servers - that's just how shared hosting usually is.
Cloudflare must have brilliant marketing so that people fall for it 