You may be right generally, but for your specific example that's not email being rubbish it's Google being rubbish. Why not switch to a professional provider?
Yes. Google's implementation of email. One of the most highly used email implementations on the planet.
That was just one example, I've seen corporate Exchange systems do the same. Are they not professional?
If one of the biggest email providers on the planet can silently swallow and not deliver emails, then blanket statements saying emails never fail are just wrong. It's important to understand practical failure modes of the systems we use, and not pretend they're more perfect than they are in reality.
It's funny that always when email fails, the next word is gmail, maybe go away from that wannabe email service? And no dont tell me a private server is impossible, i manage more then 150 (from different customers) of them and have zero problems with delivery to gmail ms etc, but yes you need to veryfi your domain @ google and microsoft.