The Only Valid Throwaway Email Address

2023-10-11 20:53:52Z (last updated 2023-10-15 11:22:28Z)

For what exactly?

The specific use case here is something like Realm Studio, where you want to use the app, but the app wants your email address for no reason. You also do not want anyone to receive a garbage email. What do you put in?

Realm Studio documentation

If you do not care about receiving emails {id=no-email-receive}

Well, since I didn't care about receiving emails, I just put in nobody@nowhere.invalid (and also denied network access for the app, it wasn't required anyways). Then I moved on with using the app.

You might ask: "How is that a valid email address?"

Well, first of all, programmers definitely don't know how to validate an email address

"Your E-Mail Validation Logic is Wrong"

Second of all, that's basically the perfect throwaway address, if you're not planning to receive any emails, that is. Because it is impossible to send emails to that address, thanks to the top level domain.

The top level domain in the case of nobody@nohwere.invalid is .invalid. The .invalid top level domain is a reserved domain, defined in RFC 2606. It's not supposed to be resolvable by DNS, which makes email not work, as it relies on DNS data to send emails to a domain.

RFC 2606

Alternatives

If the above doesn't work, another alternative based on RFC 2606 is example@example.com. It is based on a real domain name that you can actually visit, but it is primarily for illustrative purposes. It's also reserved, so emails don't really get to anyone (unless someone decides to setup an email server on example.com).

Weirder alternatives (and less suggested)

If those don't work though, this is the last resort and must be used carefully: a@a.aa.

There's reasons to not use that and instead the above already suggested email address. Top Level Domain names which are 2 characters long are country TLDs, meaning a country controls their 2 character TLD. If there's a country which the short code for it is aa, then there will be an .aa TLD, which might allow registering a.aa which someone could setup an email server for.

That's quite long. Summary is: In the future, it might become a real domain which then receives your emails.

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