Set up your domain (host-specific instructions)
To start using a custom domain (contoso.com) with Office 365, you need to verify your domain and configure your domain's DNS records.
You can add and manage DNS records using the administrative tools at your domain host, or give Office 365 control of your domain records and we'll set them up for you.
Click your domain host below for the exact steps. If you're not sure who your host is, see Find your domain registrar.