The Message Delivery Component (MDC) is used to deliver messages from OAS to your users via SMS, email, voice, or push notification.
The SMS, email and voice gateways have to be purchased separately from another provider or you can bring your own. The push notification gateway can be a custom integration or the DIGIPASS Gateway (which can be found on the OAS installation ISO). The push notification gateway will use Firebase or Apple Push Notification Services to deliver the notifications to the user.
All of these services can be configured from the MDC Config Utility. On linux you can start it by running
mdcconfiggui as root and on windows by opening