cportal3.visa.com has no MX records.
Question and response
Question
dig cportal3.visa.com. MX
Answer
The response has no answer records.
Authority
visa.com. 300 SOA lloyd.ns.cloudflare.com. dns.cloudflare.com. 2019111384 10000 2400 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0