See RFC 5322: Internet Message Format and, to a lesser extent, RFC 5321: Simple Mail Transfer Protocol. RFC 822 also covers email addresses, but it deals mostly with its structure: And as usual, Wikipedia has a decent article on email addresses: The local-part of the email address may use any of these ASCII characters: uppercase … Read more
The shortest valid email address may consist of only two parts: name and domain. name@domain Since both the name and domain may have the length of 1 character, the minimal total length resolves to 3 characters.
Using regular expressions is probably the best way. You can see a bunch of tests here (taken from chromium) Here’s the example of regular expresion that accepts unicode: But keep in mind that one should not rely only upon JavaScript validation. JavaScript can easily be disabled. This should be validated on the server side as well. Here’s an example of … Read more
I have this function to validate an email addresses: Is this okay for checking if the email address is valid or not?
The fully RFC 822 compliant regex is inefficient and obscure because of its length. Fortunately, RFC 822 was superseded twice and the current specification for email addresses is RFC 5322. RFC 5322 leads to a regex that can be understood if studied for a few minutes and is efficient enough for actual use. One RFC 5322 compliant regex … Read more
The fully RFC 822 compliant regex is inefficient and obscure because of its length. Fortunately, RFC 822 was superseded twice and the current specification for email addresses is RFC 5322. RFC 5322 leads to a regex that can be understood if studied for a few minutes and is efficient enough for actual use. One RFC … Read more