C# code to validate email address

2019-01-01 05:09发布

问题:

What is the most elegant code to validate that a string is a valid email address?

回答1:

What about this?

bool IsValidEmail(string email)
{
    try {
        var addr = new System.Net.Mail.MailAddress(email);
        return addr.Address == email;
    }
    catch {
        return false;
    }
}

To clarify, the question is asking whether a particular string is a valid representation of an e-mail address, not whether an e-mail address is a valid destination to send a message. For that, the only real way is to send a message to confirm.

Note that e-mail addresses are more forgiving than you might first assume. These are all perfectly valid forms:

  • cog@wheel
  • \"cogwheel the orange\"@example.com
  • 123@$.xyz

For most use cases, a false \"invalid\" is much worse for your users and future proofing than a false \"valid\". Here\'s an article that used to be the accepted answer to this question (that answer has since been deleted). It has a lot more detail and some other ideas of how to solve the problem.

Providing sanity checks is still a good idea for user experience. Assuming the e-mail address is valid, you could look for known top-level domains, check the domain for an MX record, check for spelling errors from common domain names (gmail.cmo), etc. Then present a warning giving the user a chance to say \"yes, my mail server really does allow