PHP Regex: Detect multiple periods, underscores, etc. in email address

Question

I have a regex expression that matches GREAT against emails like email@example.com, but can't match it against email.this.one@example.com. The strange thing is, something like this.1.b@yahoo.com works perfectly. I have used regex101.com to test my expressions, they should be matching but they're not when I actually run it on my WAMP server!

/\s(((\w)+\.)?)+((\w)+)@/

Can someone tell me what I'm missing??? I mean, I'm matching with a SPACE before the rest of the expression on purpose, since I recently read that an email address can really contain ANY keyboard character except more than one consecutive period- of course, I know it's only detecting alphanumeric characters in front of the other periods that are matched right now before the @ symbol, but that's besides the point.

Answer 1

You will have to do a lot of work to verify any email that could exist.

The much better option is to actually verify the email by sending the email and doing a confirmation. And the validation that is enough for that is that the email contains an @ sign.

You want to go the regex way and not miss any emails that might be entered? Here's the full RFC-822 compliant regex :

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)+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:
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