SMEX EUQ approved sender management only works on Microsoft Outlook on Windows platform. It does not work on Outlook Web Access (OWA), Outlook for Mac, or Mac OS default mail application.
During SMEX installation, enabling spam prevention settings along with selecting "Integrate with End User Quarantine" allows the Spam folder to be synced between Exchange server and email clients, including Outlook for Windows, Outlook for Mac, MacOS default Mail app and OWA. SMEX is able to detect spam messages and deliver them to the Spam Folder. However, on OWA, Outlook for Mac and MacOS default Mail application, the Approved Sender management cannot work, which is a known issue. This feature only works on Windows version of Outlook.