mail.affingroup.com has no MX records.
Question and response
Question
dig mail.affingroup.com. MX
Answer
The response has no answer records.
Authority
affingroup.com. 1800 SOA bonnie.ns.cloudflare.com. dns.cloudflare.com. 2397903912 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0