mail-1.fortimailcloud.com has no MX records.
Question and response
Question
dig mail-1.fortimailcloud.com. MX
Answer
The response has no answer records.
Authority
fortimailcloud.com. 120 SOA ns3.fortinet.com. mis.fortinet.com. 2026014130 10800 15 604800 120
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0