How to: Verify That Strings are in Valid E-Mail Format
The following code example uses the static Regex.IsMatch method to verify that a string is in valid e-mail format. The IsValidEmail method returns true if the string contains a valid e-mail address and false if it does not, but takes no other action. You can use IsValidEmail to filter out e-mail addresses containing invalid characters before your application stores the addresses in a database or displays them in an ASP.NET page.
Example
Function IsValidEmail(strIn As String) As Boolean
' Return true if strIn is in valid e-mail format.
Return Regex.IsMatch(strIn, "^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$")
End Function
bool IsValidEmail(string strIn)
{
// Return true if strIn is in valid e-mail format.
return Regex.IsMatch(strIn, @"^([\w-\.]+)@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([\w-]+\.)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$");
}