I’m currently migrating most of my self-hosted WordPress blogs from my server to WordPress.com hosting, which allows you to use your own domain.

But setting the DNS records from your registrar may trigger some errors. I myself wasn’t able to properly update my domain configuration and OVH always sent me back this notification email each time I tried to update the DNS record of mydomain.fr:

DNS update failed. Fix the zone-check error, and relaunch the operation.
The zone-check error is: [TEST SOA record exists]: answer refused by the server: (SOA mydomain.fr)

This errors is mostly due to the use of a non-US domain.

To fix this SOA-related issues, the only extra step required consist in asking WordPress.com to set a zone record on their servers. After that, you can proceed to the standard mapping procedure.