mail50.elavon.com has no CNAME records.
Question and response
Question
dig mail50.elavon.com. NS
Answer
The response has no answer records.
Authority
elavon.com. 180 SOA ns1.elavon.com. domainadmin.usbank.com. 2026030208 300 600 86400 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0