email validation in a c# winforms application

Question

Hi how can i validate email in c# winforms ?

Answer 1

You can use Regular Expressions to validate Email addresses:

RegEx reg=new RegEx(@"^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,6}$", RegexOptions.IgnoreCase); ///Object initialization for Regex 
if(reg.IsMatch("email string"))
    //valid email

Answer 2

The best way would be to forward this validation task to .NET itself:

public bool IsValidEmailAddress (string email)
{
    try
    {
        MailAddress ma = new MailAddress (email);

        return true;
    }
   catch
   {
        return false;
   }
}

Granted, it will fire false positives on some technically valid email addresses (with non-latin characters, for example), but since it won't be able to send to those addresses anyway, you can as well filter them out from the start.

Answer 3

This page has a good regular expression matching email addresses.

Remember this is only a formal check. To check whether an email address really exists, you have to send an actual email to the address and check the mail server's response.

And even if this succeeds, the SMTP server might be configured to ignore invalid recipient addresses.