Every domain on your account can have its own mailboxes.
HOW
Add the domain to the account first, under cPanel > Domains. Then cPanel > Email Accounts > Create, and choose that domain from the dropdown.
The mailboxes are entirely separate from those on your main domain.
WHAT TO CHECK
Each domain needs its own SPF and DKIM records for mail to authenticate properly. cPanel > Email Deliverability shows the status for every domain, and repairs it where we host the DNS. AutoSSL should cover the mail hostname for that domain, so devices connect without certificate warnings. MX records must point at our server for that domain, unless you route its mail elsewhere.
MANAGING SEVERAL BRANDS
Set up each person's device with both addresses rather than forwarding everything into one inbox, so replies go out from the right brand.
Set the default identity carefully. Replying to a customer of one brand from the other brand's address is the sort of mistake that is hard to explain.
CONSOLIDATING
If a second brand is retired, keep its domain and forward its addresses to the main brand for at least a year.
