As you set up your Professional Email account, you might see some domains listed as not eligible or grayed out in your Tso Client Area: - Services - My Services - Select the service in question. This is because you can only have one type of email account for each domain.

For example, you'll get an error message if you try to set up a Professional Email account with a domain that's already used by Microsoft 365.

The following can't be transferred to any other platforms: