[Reference: Microsoft Documentation - Enable Mailboxes for Dynamics 365,  Add the Dynamics 365 App for Outlook Security Role:, Users need to be assigned the Dynamics 365 App for Outlook security role to access the app. This role grants the necessary permissions to interact with Dynamics 365 through Outlook., Assigning this role ensures that users have the correct access rights to use the app within their Outlook environment., Reference: Microsoft Documentation - Security Roles for Dynamics 365 App for Outlook, ]