Fastmail is also nice imho.

(no affiliation, just a happy family plan customer paid far into the future)

the only minuses of these services, is that because they are not trusted, they are rejected by some websites, and they are flagged as spam :/

For example fastmail.com is considered as a fake account registration provider, because of the masked email feature, that allows you many times to register to a free trial.

It's the only reason I stay with Gmail, despite their terrible practices

My strong advice would be to buy your own domain, otherwise you're letting a third party own a lot of your digital life.

Strongly agree with this, I own my own domain for mail and service routing (with services hanging off of subdomains).

I have been using Mailfence and Zoho (paid plans as well as free plans) for almost a decade. Never had any issues. Support is actually reachable and good. (no affiliation). IMAP works only on paid plans

I’m moving to Proton as we speak :-)