Get all subdomains of a domain

GetDomainSubdomains

/// <summary>
///  Get all labels of the domain. Item 0 is always TLD.
/// </summary>
/// <param name="domain"></param>
/// <returns></returns>
public static IEnumerable<string> GetDomainSubdomains(string domain)
{
    var parts = domain.Split('.').ToArray();
    var labels = new List<String>(parts.Length + 1);
    for (var i = 0; i < parts.Length; i++)
    {
        labels.Add(String.Join(".", parts.Skip(i)));
    }
    return labels;
}