mail.gymmasteronline.com has no MX records.
Question and response
Question
dig mail.gymmasteronline.com. MX
Answer
The response has no answer records.
Authority
gymmasteronline.com. 300 SOA ns1.linode.com. info.gymmastersoftware.com. 2021027194 120 300 1209600 300
Additional
. 0 OPT ; payload 1024, xrcode 0, version 0, flags 0