从 Windows 服务发送电子邮件:事务失败.服务器响应为 5.7.1 客户端主机拒绝访问被拒绝

Question

下面的代码在Windows Form中工作正常，但在Windows服务中不起作用。该服务在 Windows XP 上运行。

我尝试更改登录用户，但没有工作。

错误：事务处理失败。 服务器响应为 5.7.1 客户端主机 拒绝访问被拒绝

private void SendEmailToHO()
{
    try
    {
        int mailSentSuccessfully = 0;
        MailAddress to = new MailAddress(mailTo);
        MailAddress from = new MailAddress(mailFrom);
        using (MailMessage mail = new MailMessage(from.Address, to.Address))
        {
            int attachmentCount = 0;
            try
            {
                foreach (string fileName in fileEntries)
                {
                    Attachment attachment = new Attachment(fileName);
                    mail.Attachments.Add(attachment);
                    attachmentCount++;
                }
                SmtpClient client = new SmtpClient(mailHost, port);
                if (enableSSL == "Y")
                {
                    client.EnableSsl = true;
                }
                client.DeliveryMethod = SmtpDeliveryMethod.Network;
                client.UseDefaultCredentials = false;
                client.Credentials = new System.Net.NetworkCredential(mailUser, mailPassword);
                mail.Subject = "Email Subject " + clientID;
                mail.Body = "Attached please find the files: " + clientIDTitle;
                if (attachmentCount > 0)
                {
                    //
                    client.Send(mail);
                    //if no error, this code will work.
                    mailSentSuccessfully = 1;
                    new MyApp.LogWriter("Sent mail to " + to.Address + ", nAttachment count = " + attachmentCount);
                }
                else
                {
                    new MyApp.LogWriter("Attachment count = " + attachmentCount);
                }
            }
            catch (Exception ex)
            {
                new MyApp.LogWriter("Send mail failed. Cause: " + ex.Message
                                          + "n Inner Exception: " + ex.InnerException);
            }
        }
    }
    catch (System.Exception ex)
    {
        new BTCClient.LogWriter("Email Error '" +
                           ex.Message + "'");
    }
}

Answer 1

我遇到了同样的问题，要解决此问题，您需要联系电子邮件服务器的服务提供商，并告诉他们授予对您的服务器IP的访问权限。