DNS connections

In 2021, I bought a domain and connected it to a Microsoft 365 account at the time. Over the years, I did not renew the domain and the 365 membership.

Luckily last month, the domain was still available so I bought it back. Now, I can’t connect it to my new 365 account because it is still connected with the old one. I don’t have the username so I’m stuck at the moment