在outlook中撰写带有附件的电子邮件

在我的应用程序中，我有一个要求，如果用户单击发票编号，生成的发票报表将附加到outlook中的合成电子邮件。使用下面的代码，我能够发送自动电子邮件，但我需要只是撰写和打开outlook窗口的用户审查和编辑的内容。不要发送。请帮助。

public void pdfStatement(string InvoiceNumber)
 {
     InvoiceNumber = InvoiceNumber.Trim();
     string mailServer = "server";
     string fileName = InvoiceNumber;
     string filePath = Server.MapPath("~/Content/reports/");
     string messageBody = "Its an automated test email, please ignore if you receive this.";
     CreateMessageWithAttachment(mailServer, filePath, fileName, messageBody);
 }

  public void CreateMessageWithAttachment(string mailServer, string filePath, string fileName, string messageBody)
      {
     MailMessage message = new MailMessage (
                                            "user@domain.com",
                                            "user@domain.com",
                                            "TestEmail",
                                             messageBody);
      filePath = filePath + fileName + ".pdf";
     // Create  the file attachment for this e-mail message.
     Attachment attach = new Attachment(filePath);
     attach.Name = fileName + ".pdf";
     // Add the file attachment to this e-mail message.
     message.Attachments.Add(attach);
     //Send the message. 
    SmtpClient client = new SmtpClient(mailServer);
     var AuthenticationDetails = new NetworkCredential("user", "password");
     client.Credentials = AuthenticationDetails;
     client.Send(message);
 }