autoconfig.migadu.com has no CNAME records.
Question and response
Question
dig autoconfig.migadu.com. NS
Answer
The response has no answer records.
Authority
migadu.com. 1383 SOA ns0.migadu.com. hostmaster.migadu.com. 1772870553 1200 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0