za-smtp-inbound-2.mimecast.Co.Za IXFR zone transfer

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 za-smtp-inbound-2.mimecast.Co.Za is not the root of its zone.
Instead, try zone transfer on mimecast.Co.Za .