> Well, I don't know in which world you live, but in mine Outlook is alive and kicking, that's where purchase orders are confirmed, meetings with suppliers are organized, business decisions are made

Stuff like that was what I meant. I wouldn't call receipts, calendar invitations and verification emails "communication" (as in person to person). I agree though that email is a prime medium for B2B communication, but within a company you'd usually use another medium (like Slack).