A single domain serves either Google Workspace or Maildoso SMTP — not both. Google and SMTP use different DNS/MX configurations, so each domain has to be assigned to one of them, and the split is not automatic.
On combo plans (for example 150 Google + 150 SMTP), if all of your domains were connected to Google Workspace during setup, the SMTP half of your plan has no domains to land on yet — even though your SMTP allotment is intact. This is why you may see "all my domains show Google, I can't use my SMTP."
What to do:
Decide how many domains you want on Google vs SMTP.
Contact support — we set up the SMTP-side domains for you on the backend (switching some domains from Google to SMTP, or adding SMTP domains).
If you created SMTP mailboxes by mistake and want Google Workspace on the eligible domains (or vice versa), let support know and we will reallocate them.