Regular Expressions are very helpful in various programming languages.

 

if email with display name is an valid email address

/// <summary>
/// check if email with display name is an valid email address
/// </summary>
/// <param name="emailAddress">email address who wants to check which</param>
/// <returns Type="bool">returns true if email with display name is valid email, otherwise returns false</returns>
protected static bool isValidMailAddressWithDisplayName(String emailAddress)
{
Regex regExp = new Regex(@"^((?<displayname>[\w\s'-]+)(?<address><[\w\.]+@([\w\d-]+\.)+[\w]{2,4}>)(\;|$))+$");

return regExp.IsMatch(emailAddress);
}
C# Code example