In order to enable MPP, users must have Apple devices, configure their email account to use Apple Mail applications, update their operating system to the latest version, and opt into MPP. 

Inner Join Venn Diagram

Venn diagrams are a more restrictive form of Euler diagrams

An Euler diagram (/ˈɔɪlər/, OY-lər) is a diagrammatic means of representing sets and their relationships. They are particularly useful for explaining complex hierarchies and overlapping definitions. They are similar to another set diagramming technique, Venn diagrams. Unlike Venn diagrams, which show all possible relations between different sets, the Euler diagram shows only relevant relationships.