Issue with validate email using PHP

Question

I have the following code to check if user input is a valid email, there might be a few questions already about this but noone seems to validate the PHP function.

/* check if valid email*/
public function isValidEmail($email){
    if(filter_var($email, FILTER_VALIDATE_EMAIL)) {
        return true;
    }
    return false;
}

If we do a test using this function:

isValidEmail('some?=Wrong@mail.com')

This should return false because characters like ?= are inside the email address. Is there a stricter way to check email?

By "to write out nothing" - Do you mean it returns true with the test input? — Epodax, Mar 01 '16 at 13:34
You pass the variable to your function as `$epost` but then access it as `$email` - this won't check the passed variable. — Luke, Mar 01 '16 at 13:37
See this: http://stackoverflow.com/questions/19220158/php-filter-validate-email-does-not-work-correctly your test address seems in fact valid. — Bart Friederichs, Mar 01 '16 at 13:40
all the more reasons I never liked that filter/function, and they said I was *"the crazy boy who cried wolf"* — Funk Forty Niner, Mar 01 '16 at 13:41
See this Question / Answer http://stackoverflow.com/questions/2049502/what-characters-are-allowed-in-email-address - those characters are valid in the local part of the email address. — Luke, Mar 01 '16 at 13:41
Allright, it seam that everything is a legal email adress thise days! thanks for the heads up! — sdfgg45, Mar 01 '16 at 13:43

score 2 · Accepted Answer · edited May 23 '17 at 12:15

The problem here is that ? and = are perfectly valid for an email address. From Wikipedia on the RFC controlling email addresses

The local-part of the email address may use any of these ASCII characters:
These special characters: !#$%&'*+-/=?^_`{|}~ (ASCII: 33, 35–39, 42, 43, 45, 47, 61, 63, 94–96, 123–126)

If you're trying to make sure the email address actually exists, just be aware that that path is very difficult

Issue with validate email using PHP

1 Answers1