Sep
10th
Thu

/^(?:[a-z\d!#\$%&'\*\+\-\/=\?\^_`\{\|\}~]+|\.)+@[a-z\d\-]+(?:\.[a-z\d\-]+)*$/i

This regular expression describes the HTML5 e-mail address syntax. The syntax is described in the spec as ABNF format

1*( atext / "." ) "@" ldh-str 1*( "." ldh-str )

But to figure out what the hell that means, you must read the ABNF format RFC, the e-mail RFC and a domain name RFC.

I’ve created a gist on github for it as well.