I had a .to domain for a while, and I had an email address "firstname@firstname.to" where firstname is my first name. I wanted to use it when I needed to give out emails causally, like if someone from Church or some other group wanted my email.

I gave up on it, not because of computer validation but because of stupid people! Nobody would "get" the .to domain and they'd always think there should be a .com or .gmail.com on the end of it. Especially older people.

So I gave it up.