Hi @ag2771 , here are some of the documents I found on the People API and relevance score, which point out the factors that affect the relevance score, If you need its algorithms, I recommend opening a support ticket to ask a back-end engineer. Hope this helps.
https://learn.microsoft.com/en-us/graph/people-insights-overview
https://learn.microsoft.com/en-us/graph/api/resources/scoredemailaddress?view=graph-rest-1.0
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