Of course not. However, in the past ~7 years, while running my own mail stack, I never had a delivery issue, though obviously this is small traffic. At work, w

Of course not. However, in the past ~7 years, while running my own mail stack, I never had a delivery issue, though obviously this is small traffic. At work, we handle pretty large traffic for mail, with self-hosted mail servers as well - those are exim. No delivery issues either, although these are only the real, important, not even remotely spam-like, core business messages. Spam-like newsletters are done via sendgrid there.