He's being a bit whiny here. He was having employees use Gmail as a client for his self-hosted POP mail, which is a niche use case that likely has a brittle implementation and doesn't make any money for Google. Gmail offers a paid product for this kind of use case, but it won't integrate with the rest of his (likely custom) automation. He wants to self-host parts of the system and have Google do the messy bits, but he's not their customer and probably isn't a very good product either.
He then complains that to self-host IMAP:
My server is now responsible for storing all of their messages, including all of their spam. It is a vast amount of data. I will have to implement quotas.
It's 2025 and that's a silly claim. A 12Tb HDD costs the same as a couple bottles of booze, and it's not hard to write a script that clears out spam after 30 days. The other complaints are basically UX.
Normally saying a small business owner should self-host IMAP and write scripts would be a bit unreasonable, but this is JWZ.

