Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi Sachie10,
Greetings.
May I know whether you are an Office 365 user which you mentioned it gives the error "We couldn't find a mailbox for this recipient. Either they don't have a mailbox or don't have a license assigned"? If so, you can refer to Leonard's reply to check whether the user has been soft deleted or check if it can be restored. Please be noted that you may need to contact your admin for help as the detailed performance needs to be done by an admin. Also, a screenshot about the error is also appreciated.
Regards,
Alan