[font size=3]我在《C#数据库系统开发案例精选>>企业客户资源管理里面的邮件发送中遇到了发送失败的问题，我想请教大家，这是我添加按钮的代码：
  [font size=2]try
                {
                    string file = Application.StartupPath + "testXML.xml";
                    System.Net.Mail.MailMessage mymail = new MailMessage();
                    mymail = new System.Net.Mail.MailMessage(txtSEmail.Text.Trim(), txtCEmail.Text.Trim());
                    mymail.Subject = txtETitle.Text.Trim();
                    mymail.Body = txtEContent.Text.Trim();
                    if (cboxAccessories.Items.Count > 0)
                    {
                        for (int i = 0; i < cboxAccessories.Items.Count; i++)
                        {
                            System.Net.Mail.Attachment myattachment = new System.Net.Mail.Attachment(
                                cboxAccessories.Items[i].ToString(), System.Net.Mime.MediaTypeNames.Application.Octet);
                            System.Net.Mime.ContentDisposition disposition = myattachment.ContentDisposition;
                            disposition.CreationDate = System.IO.File.GetCreationTime(file);
                            disposition.ModificationDate = System.IO.File.GetLastWriteTime(file);
                            disposition.ReadDate = System.IO.File.GetLastAccessTime(file);
                            mymail.Attachments.Add(myattachment);
                        }
                    }
                    System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient(
                        txtSService.Text.Trim(), Convert.ToInt32(txtServicePort.Text.Trim()));
                    client.Credentials = new System.Net.NetworkCredential(txtUName.Text.Trim(), txtUPwd.Text.Trim());
                    client.Send(mymail);
                    MessageBox.Show("邮件发送成功!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                }[/font][/font]
调式的时候全部过了 到  client.Send(mymail);这里就没有执行成功