生成服务器的SMTP邮件发送邮件失败（window8）

Question

SMTP异常在System.Net.Mail.SmtpClient.Send（MailMessage消息）中发送mail.SMTP异常失败 我已附上以下代码，请查找代码： 使用System.net.mail

try
    {

        Load_LDAP_Details();
        string subject = "Test SUbject";
        string body = "This is a test body";
        MailMessage mail = new MailMessage("abc@gmail.com", emailTo);
        SmtpClient client = new SmtpClient();
        client.Port = 25;
        client.DeliveryMethod = SmtpDeliveryMethod.Network;
        client.UseDefaultCredentials = false;
        client.Host = "smtp.server.com";
        mail.Subject = subject;
        mail.Body = body;
        mail.IsBodyHtml = true;
        client.Send(mail);
        client.EnableSsl = false;
        lblEmail.Text = "sent";

       client.Credentials = CredentialCache.DefaultNetworkCredentials;


    }
    catch (Exception ex) {

        string message = string.Format("Time: {0}", DateTime.Now.ToString("dd/MM/yyyy hh:mm:ss tt"));           

        message += string.Format("Message: {0}", ex.Message);

        message += string.Format("StackTrace: {0}", ex.StackTrace);

        message += string.Format("Source: {0}", ex.Source);

        // message += string.Format("TargetSite: {0}", ex.TargetSite.ToString());


        lblEmail.Text = message;

    }