I personally have a dot-email address.

And you left out dot-edu.

And I get a fair bit of ham from other weird TLDs. So I think a whitelist is a bad idea. But that's because I prefer to have some spam get through than have ham get blocked by mistake. Even with my very sloppy algorithm, the only time spam ends up in my inbox is if a spammer spoofs one of my contacts, and that is extremely rare.

I knew I was forgetting one, thanks for reminding me about .edu.

There is also .mil though I have not actually seen that one used in a very long time.

As a B2B SaaS company, most of our legitimate, paying customer base uses .app or .io domains.

.co.uk isn't a country TLD, .uk is. If you block .ac.uk you'll block every UK university, .gov.uk the UK government and if you block .me.uk you'll block, well, me.

as someone that’s never needed SEO perks of a .com since none of my customers would use a search engine to find me (they’ll click thru from posts and ads on social media and group chats)

I typically register both a new TLD and a .com, and I use the .com for the email campaigns and reply-to

if it gets flagged that doesnt affect my more official one-to-one emails from the actual domain

so I would say, maybe? because I’m not allergic to “bloody stupid” TLD’s and have already adapted to what you’re wondering about

There are lots of businesses using `.io` `.ee` `.co` etc that depending on your email use-case would be detrimental to block especially if you're doing any kinds of business or outreach.

Those are country code TLDs

In name only. Domains with those TLDs are available to anyone willing to pay.

This was in the original comment:

> Honest question: Is there any reason to not just blacklist all emails from TLDs that aren't the Big Four (.com, .net, .org, .gov) and country TLDs (eg: .co.uk, .jp, etc.)?

I setup my website and email at a dot-tech because, surprise, I work in tech and the equivalent com and io were taken and/or prohibitively expensive

That's exactly the kind of arbitrary bullshit policy we don't need more of.

There‘s also the fancier new stuff like .ai and .io.

Aren't both of those country TLDs?

Yep, .ai is the TLD of Anguilla (United Kingdom) and .io is British Indian Ocean Territory (United Kingdom).

https://en.wikipedia.org/wiki/Country_code_top_level_domain

Oh, wasn‘t even aware. Today I learned.

My company has a .tech domain.