private string GetInvoiceHeaderResource(SendEmailType sendEmailType, TransactionEmailDto transactionEmailDto)
        {
            string header = "";

            switch (sendEmailType)
            {
                case SendEmailType.Invoice:
                    header = InvoiceInfo.IdInvoice;
                    break;
                case SendEmailType.Credit:
                    header = InvoiceInfo.IdCreditMemo;
                    break;
                case SendEmailType.Purchase:
                    header = ReceiptInfo.ReceiptNumber;
                    break;
                case SendEmailType.Cancellation:
                    header = ReceiptInfo.RefundNumber;
                    break;
                case SendEmailType.Payment:
                    header = ReceiptInfo.PaymentReceipt;
                    break;
                case SendEmailType.Refund:
                    header = ReceiptInfo.RefundNumber;
                    break;
                default:
                    throw new ArgumentOutOfRangeException("sendEmailType");
            }
            header += " " + transactionEmailDto.Invoice.Id;
            return header;
        }