Tell me you haven't run a large email server without telling me. There's a reason even large corporates that can easily afford the resources to run email their

Tell me you haven't run a large email server without telling me. There's a reason even large corporates that can easily afford the resources to run email their email themselves decide against it. There are a handful of good providers, not just Google and Microsoft, but the two hyperscalers do have very good offerings, so of course they have a lot of the market.