使用 ASP.NET MVC 发送电子通讯时出现 IIS 错误

Question

我在我的mvc-helper类中发送新闻通讯（大约给5000人）时遇到了问题。

public static void SendNewsletter(string fromAccount, string subject, string eMailText)
{
    var userEMailAddresses = new List<string>();

    using (var dbContext = new dbEntities())
    {
        userEMailAddresses =
            dbContext
                .User
                    .Where(w =>
                        !w.IsDeactivated &&
                        !w.IsBlacklisted)
                    .Select(s =>
                        s.UserName)
                    .ToList();
    }

    new Thread(() =>
    {
        for (int i = 0; i < userEMailAddresses.Count; i++)
        {
            SendMail(fromAccount, userEMailAddresses[i], subject, eMailText);
        }
    }).Start();
}

这是一个将在控制器中调用的函数。下面是发送函数的代码块：

public static void SendMail(string fromAccount, string toAccount, string subject, string eMailText)
{
    var fromEmailAddress = new EMailModel(fromAccount);

    var body = string.Empty;
    using (var sr = new StreamReader(HostingEnvironment.MapPath("\\App_Data\\Templates\\") + "EMailTemplate.txt"))
    {
        body = sr.ReadToEnd();
    }

    body = body.Replace("%%Subject%%", subject);
    body = body.Replace("%%Body%%", eMailText);
    body = body.Replace("%%Year%%", DateTime.Now.Year.ToString());

    using (MailMessage mail = new MailMessage(fromEmailAddress.EMailAddress, toAccount))
    {
        mail.Subject = subject;
        mail.Body = WebUtility.HtmlDecode(body);
        mail.IsBodyHtml = true;

        using (SmtpClient smtp = new SmtpClient(Statics.SmtpClient, Statics.SmtpPort))
        {
            smtp.UseDefaultCredentials = false;
            smtp.Credentials = new System.Net.NetworkCredential(fromEmailAddress.EMailAddress, fromEmailAddress.Password);
            smtp.EnableSsl = Statics.SslEnabled;
            try
            {
                smtp.Send(mail);
                Thread.CurrentThread.Join(1000);
            }
            catch (Exception ex) {
                throw ex;
            }
        }
    }
}

大约发送了1300封电子邮件后，我的IIS出现了以下错误： 我该如何解决这个问题？我需要这个新闻通讯系统...

- Henscho

---

Thread.CurrentThread.Join(1000); ？？？ - Falco Alexander

我们有一个邮件系统，在处理太多电子邮件后就会崩溃。看起来我们的邮件服务器被堵塞了，所以我们加入了一个循环计数器和等待时间，即处理10封电子邮件，等待10秒钟，反复执行。现在它运行得很好，也许值得在你的情况下进行调查？ - Hugo Yates

@FalcoAlexanderThread.CurrentThread.Join(1000)和Thread.Sleep(1000)是相同的。 - Henscho

日志中关于 IIS 工作进程失败的记录是什么？ - Paul Zahra

@PaulZahra不，所有检查都已禁用。 - Henscho

Answer 1

我发现了许多错误，为什么它不起作用。

第一个错误是在MailEnable中的安全设置。在MailEnableAdmin -> 服务器 -> Localhost -> 服务器和连接器 -> 右键单击SMTP和设置 -> 安全选项卡，有一个收件人限制（1000）的复选标记。我取消了勾选并重新启动了服务器。

之后，在我的用户列表中有一个无效的电子邮件地址。然后我创建了一个电子邮件检查功能：

    private static bool IsValidEMail(string eMailAddress)
    {
        if (Regex.IsMatch(eMailAddress, @"\A(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?)\Z", RegexOptions.IgnoreCase) && new EmailAddressAttribute().IsValid(eMailAddress))
            return true;

        return false;
    }

我已经更新了我的发送函数为

    public static void SendMail(string fromAccount, string toAccount, string subject, string eMailText)
    {
        if (!IsValidEMail(toAccount))
        {
            var invalidEMailAddress = toAccount;

            toAccount = "[e-mail]";
            subject = "E-Mail-Address is invalid";
            eMailText = String.Format("Dear Administrator,<br><br>the following E-Mail-Address is invalid:<br><br>{0}", invalidEMailAddress);
        }

        var fromEmailAddress = new EMailModel(fromAccount);

        var body = string.Empty;
        using (var sr = new StreamReader(HostingEnvironment.MapPath("\\App_Data\\Templates\\") + "EMailTemplate.txt"))
        {
            body = sr.ReadToEnd();
        }

        body = body.Replace("%%Subject%%", subject);
        body = body.Replace("%%Body%%", eMailText);
        body = body.Replace("%%Year%%", DateTime.Now.Year.ToString());

        using (MailMessage mail = new MailMessage(fromEmailAddress.EMailAddress, toAccount))
        {
            mail.Subject = subject;
            mail.Body = WebUtility.HtmlDecode(body);
            mail.IsBodyHtml = true;

            using (SmtpClient smtp = new SmtpClient(Statics.SmtpClient, Statics.SmtpPort))
            {
                smtp.UseDefaultCredentials = false;
                smtp.Credentials = new System.Net.NetworkCredential(fromEmailAddress.EMailAddress, fromEmailAddress.Password);
                smtp.EnableSsl = Statics.SslEnabled;
                try
                {
                    smtp.Send(mail);
                    Thread.CurrentThread.Join(1000);
                }
                catch (Exception) { }
            }
        }
    }

而 SendNewsletter 函数是相同的。现在，所有的电子邮件都已发送。

非常感谢所有帮助的用户！

- Henscho