.io isn't a gTLD at all, it's a ccTLD belonging to British Indian Ocean Territory (which I find to be bullshit, since those islands have no permanent inhabitants).
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.
> .io isn't a gTLD at all, it's a ccTLD belonging to British Indian Ocean Territory (which I find to be bullshit, since those islands have no permanent inhabitants).
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).
Well they did until the British exiled them all to build a US naval base on Diego Garcia. And they would very much like to return home. The UK courts have ruled in favour of the Chagossians, but they are consistently ignored by the UK and US governments.
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.