System.Net.Mail.SmtpClient.IsSystemNetworkCredentialInCache C# (CSharp) Method

        private bool IsSystemNetworkCredentialInCache(CredentialCache cache)
        {
            // Check if SystemNetworkCredential is in given cache.
            foreach (NetworkCredential credential in cache)
            {
                if (ReferenceEquals(credential, CredentialCache.DefaultNetworkCredentials))
                {
                    return true;
                }
            }

            return false;
        }