smtpld21.fortimailcloud.com has no AAAA records.
Question and response
Question
dig smtpld21.fortimailcloud.com. AAAA
Answer
The response has no answer records.
Authority
fortimailcloud.com. 120 SOA ns3.fortinet.com. mis.fortinet.com. 2026014398 10800 15 604800 120
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0