cportal4.visa.com has no MX records.
Question and response
Question
dig cportal4.visa.com. MX
Answer
The response has no answer records.
Authority
visa.com. 1800 SOA lloyd.ns.cloudflare.com. dns.cloudflare.com. 2397325998 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0