When I was setting this website up, I ran across a Wikipedia article on domain hacks. That's the official-sounding version of when a top-level domain (TLD) is part of a website's name. Things like who.is or blo.gs. It struck me that I could use India's TLD, .in, to shorten my own website's URL. I ran a whois search and it was availiable. Then it wasn't anymore. Someone had noticed my search and bought it to try and ransom the site.
That's how it works, I think. Some predatory whois sites automatically purchase domains searched, then offer to sell them back for some increased cost.
And, really, email@example.com is a pretty darn cool email.