OMG WTAF, Microsoft Outlook now allows reactions (thumbs up, hearts, etc.) to emails. Except I don't use the Outlook client. So once a day I get an automated email with all the reactions others gave to my emails. And now I have even more email.

What other features of social media should be added to email?

Maybe Microsoft Outlook can add a tip jar to their email client.

@Riedl email stories of people looking bored, furious, or sad as they read their inboxes.
@uberalex
I'm going to add you to my mailing list, I mean "circle"