Get an email address that you own, on a domain you control. Switch to a provider that takes your money for whom you are the customer - not the product.
I did this with Fastmail and Iki.fi, a Finnish non-profit[1], who have been selling people "permanent" email addresses since 1995.
That said, there are ccTLDs which behave more like gTLDs (like .io, .me, .fm, .gg, .cd) and are treated as such across much of what you do online, but whether that'll impact your email delivery depends on who you communicate with and how they treat spam.
That's not strictly true - British Indian Ocean Territory has permanent inhabitants, just not any native ones (never had had them, really - it was uninhabited until 1793). US military Diego Garcia base is there...
It's bullshit for other reasons, and expulsion of Chagossians to build the base is a tragedy - but not due it being empty territory (it's not).