Where can I see the performance of my sends in DESelect Engage?

if you want to see all the sends you’ve tracked in deselect engage and how many contacts have been actually included and excluded for each send for a given date range, you can go to the dashboard page unlike the calendar view, which is a preview/simulation of upcoming sends, the dashboard will show you the number of contacts that were processed after the send happened additionally, it allows you to filter based on specific rules and priorities you've set, to see how those rules impact your campaign performance you can see this article regarding the reporting functionality feature by selecting a specific send, you can view details on how a particular send performed after being sent out in sfmc you will be able to filter based on values for "outcome" (i e , included, excluded, or both) and "reason for exclusion" in the dashboard view of a specific send