pmta.ungapped.io has no CNAME records.
Question and response
Question
dig pmta.ungapped.io. NS
Answer
The response has no answer records.
Authority
ungapped.io. 3600 SOA ns1.loopia.se. registry.loopia.se. 1772668800 14400 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0