I've not tried the new option myself so this isn't a recommendation, but if you are using iCloud for personal email yet are doing 'professional' email elsewhere
because of the custom domain, then you may not know that iCloud now supports those custom domains.
Of course there may be other reasons why you want professional email separate, such as not having it at risk should Apple decide you've broken their T&Cs because poor AI/ML says so, and they close your account.
