webmail.swiftapp.cloud has no CNAME records.
Question and response
Question
dig webmail.swiftapp.cloud. NS
Answer
The response has no answer records.
Authority
swiftapp.cloud. 9981 SOA dns1.swiftrfp.net. admin.swiftrfp.net. 2023011224 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0