Internet e-mail validation expression validates everything

Question

I'm validating input in a asp.net page but the problem is it validates e-mails like hasangürsoy@şşıı.com

My code is:

if (Regex.IsMatch(email, @"\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"))
{ valid }
else { invalid }

EDIT: I've written a question before especially to validate e-mail addresses including Turkish characters but now I don't want users to be able to input mails with Turkish characters because users mostly type Turkish characters by mistake and I cannot send mails to these addresses.

But it did not validate before. It's strange that it validates now. — HasanG, Mar 24 '11 at 12:41

score 4 · Accepted Answer · answered Mar 22 '11 at 08:56

Why don't you just use build-in System.Net.Mail.MailAddress class for email validation?

bool isValidEmail = false;
try
{
    var email = new MailAddress("hasangürsoy@şşıı.com");
    isValidEmail = true;
{
catch (FormatException x)
{
    // gets "An invalid character was found in the mail header: '.'."
}

score 3 · Answer 2 · answered Mar 21 '11 at 21:09

RFC3692 goes into great detail about how to properly validate e-mail addresses, which currently only correctly handle ASCII characters. However this is due to change, and hence your validation should be as relaxed as possible.

I would likely use an expression such as:

.+@.+

which would ensure you're not turning people away because your regular expression gives them no choice.

If the e-mail is important you should be following it up with verification usually done via sending an e-mail to the supplied address containing a link.

score 3 · Answer 3 · answered Mar 21 '11 at 21:09

3

I recommend you reading this: http://www.codeproject.com/KB/validation/Valid_Email_Addresses.aspx

answered Mar 21 '11 at 21:09

vinayvasyani

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Internet e-mail validation expression validates everything

3 Answers3

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