mail.michigandigital.com has no MX records.
Question and response
Question
dig mail.michigandigital.com. MX
Answer
The response has no answer records.
Authority
michigandigital.com. 1800 SOA monika.ns.cloudflare.com. dns.cloudflare.com. 2397891653 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0