In Sitefinity 5.1 we are using our NotificationService implementation for sending out message jobs (like Workflow notification emails). For more information on configuring workflow notifications through NotificationsService, please check point 8. from this article
form our documentation.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items