Select Tools > Accounts to check your account type.
To use this feature, you need a Microsoft 365 work or school account, or an Exchange on-premises account. Supported applications include Outlook for Microsoft 365 and Outlook 2019 for Mac version 15.35 (170610) and later (select Outlook > About Outlook to check your version). Read receipts and delivery notifications are available in only some versions of Outlook for Mac, and only when using a Microsoft 365 work or school account, or an Exchange Server account managed by your organization. Outlook for Microsoft 365 for Mac Outlook 2021 for Mac Outlook 2019 for Mac Outlook 2016 for Mac More.