This domain must be the one which belongs to the Business, that's, this domain really should be the one you've registered with Microsoft 365. To learn more, see Increase a domain to Microsoft 365. You need to use the file add option to add a diagnostic file, such as https://vmware-migration55555.amoblog.com/how-much-you-need-to-expect-you-ll-pay-for-a-good-zimbra-support-premium-48428007