Changes since SOA version
IXFR is a zone transfer request that returns changes since a specific SOA version. Enter the SOA version to request changes since then.
Not an apex domain
The domain o0d2g8e95ij01q7028qc931hk5vce7fd.smtp.dk is not the root of its zone.
Instead, try zone transfer on smtp.dk .
Instead, try zone transfer on smtp.dk .