I also rely pretty heavily on this feature for a few very low traffic domains that I need but only have super set up on super clunky web mail, so I guess I'm in the market for a new mail client :(

At worst you can write a mail client to do that by logging in, listing mails, mailing them to you and keeping track of what it already sent (sqlite?) They are very well known protocols with plenty of implementations, so probably a LLM can write the code with not much guidance.

POP access of a different account on the web would be the "Check mail from other accounts"

Doesn't surprise me too much though, Gmail hasn't seen much maintenance and polish over the last few years.

I have a test suite that accesses a gmail account through POP. It's a regular gmail account. Will that be affected?

Edit: Okay I think not. But man is this confusing over whether it's Gmail that's doing the fetching over POP (a feature I had no idea existed) or somehting they're calling a third-party account fetching Gmail emails over POP.