EPP加Excel作为附件

嗨，我正在使用EPPPlus返回excel文件，并将同一文件作为附件发送。我可以打开excel文件，也得到了附件，但当我打开电子邮件附件时，我收到错误消息，说文件已损坏。请查看贝尔沃代码并建议我更改。

 MemoryStream outputStream = new MemoryStream();
                using (ExcelPackage pck = new ExcelPackage(outputStream))
                {
                    //Create the worksheet
                    ExcelWorksheet ws = pck.Workbook.Worksheets.Add("Demo");
                    //Load the datatable into the sheet, starting from cell A1. Print the column names on row 1
                    ws.Cells["A1"].LoadFromDataTable(tbl, true);
                    //Format the header for column 1-3
                    using (ExcelRange rng = ws.Cells[1, 1, 1, tbl.Columns.Count])
                    {
                        rng.Style.Font.Bold = true;
                        rng.Style.Fill.PatternType = ExcelFillStyle.Solid;                      //Set Pattern for the background to Solid
                        rng.Style.Fill.BackgroundColor.SetColor(Color.FromArgb(79, 129, 189));  //Set color to dark blue
                        rng.Style.Font.Color.SetColor(Color.White);
                    }
                    //Example how to Format Column 1 as numeric 
                    using (ExcelRange col = ws.Cells[2, 1, 2 + tbl.Rows.Count, 1])
                    {
                        col.Style.Numberformat.Format = "#,##0.00";
                        col.Style.HorizontalAlignment = ExcelHorizontalAlignment.Right;
                    }
                    MailMessage mail = null;
                    try
                    {
                        mail = new MailMessage();
                        mail.From = new MailAddress("placescms@adidas-group.com", "Adidas SystemMail");
                        mail.To.Add(new MailAddress(emailAddress));
                        mail.Subject = "Store Finder Geocoding";
                        mail.IsBodyHtml = true;
                        string message = "";
                        message += ".LLHere is the attachment with list of stores and geocode values you requested." + "</br>";
                        mail.Body = message;
                        outputStream.Position = 0;
                        Attachment attachment = new Attachment(outputStream, "Geocoding.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
                        mail.Attachments.Add(attachment);
                        mail.SubjectEncoding = System.Text.Encoding.UTF8;
                        mail.BodyEncoding = System.Text.Encoding.UTF8;
                        SmtpClient client = new SmtpClient("localhost");
                        client.Send(mail);
                    }
                    catch (Exception ex)
                    {
                        //throw ex;
                    }
                    Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
                    Response.AddHeader("content-disposition", String.Format(CultureInfo.InvariantCulture, "attachment; filename={0}", "geo.xlsx"));
                    Response.BinaryWrite(pck.GetAsByteArray());
                    Response.End();

// ...
mail.Body = message;
pck.Save();
outputStream.Position = 0;
Attachment attachment = new Attachment(outputStream, "Geocoding.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
mail.Attachments.Add(attachment);
// ...