Aside: isn't it weird how often "email addresses" is shortened to "emails"? At first glance I had to contextually infer whether it was 215M addresses or 215M messages (pieces of mail) because we also often shorten the latter to "emails" when working through our inboxes.

If you're running a marketing campaign and say "today we finally hit 1000 emails" without further clarification, nobody will know if that's 1000 subscribers or 1000 newsletters.