Simon Willison’s Weblog

Mailinator and email validation

So, Mailinator (via Joel). It’s a brilliant concept; whenever a site you don’t trust insists on you giving them an email address you invent something-random@mailinator.com and give them that instead. Then you go to the Mailinator site, enter the something-random and see the emails recently sent to that address.

As someone who dislikes having to tell sites my email address I love it. As someone who has run sites which insist on an email address I’m not so sure. Forced email registrations are frequently abused for harvesting emails for unwanted mail-outs, but they serve a very valuable purpose in protecting sites from abuse. If user’s have to provide a “real” email address to sign up, you’ve got something concrete with which to ban them should they abuse your service. Sure, these days many people have a multititude of addresses but it’s still a very useful deterrent against abuse. As services like Mailinator become more widespread, I can see web application maintainers needing to fight a constant battle to ban specific email providers from being used to sign up for accounts. It’s that, or move to manually vetting every account which adds delays and seriously reduces people’s motivation for signing up in the first place.