Avoid .io; it’s not reliable and raises ethical questions:

[0] https://web.archive.org/web/20171113150544/https://getstream...

[1] https://plan.io/blog/moving-from-planio-to-planiocom/

[2] http://www.thedarksideof.io

> [2] http://www.thedarksideof.io

Wow, didn't know this story. Imperialism at its finest from the Anglo-saxon world (well, actually started by the French with slavery but that was >200 years ago, I found way worse the decisions took 50 years ago).

.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.

Do not use .dev, some companies are using .dev for internal dev hosts and might be blocking on DNS level all external dev addresses.

The sysadmins at these companies must be laid off right now. Same with Windows admins using .local for their AD domain name, now you shot yourself in the foot never being able to sign some services with globally trusted certificates.

What? Many of these domains date back to when there were like 10 gTLDs and adding a new one was a rare event.

This doesn't mean you've ever been able to get signed certificates for nonexistent TLDs. If a TLD were to stop existing i would excuse the administrators who set up their systems under that domain, but if you're setting anything up that isn't under an available TLD you're doing it wrong.

RFC2606 dates to 1999, so they've had a little time to migrate. tl;dr: .test .example .invalid .localhost

I have a .is and .co that I hope are considered well-known .

Only if you are Icelandic or Colombian (respectively).