如何处理system.net.mail.smtpfailedrecipientexception接收失败

本文关键字：smtpfailedrecipientexception mail 失败 net system 何处理处理 | 更新日期: 2023-09-27 18:12:18

我想发送电子邮件到多个地址(超过1000个用户)，并使用以下代码，当我使用它发送电子邮件到少于100个用户它的工作，但对于超过100个用户它不工作，抛出smtpfailedrecipientexception失败的收件人!为什么?我怎样才能发送电子邮件到有效的地址，并得到这个错误的便车?

public void SendMailMessage (string[] to,string message,string subject) 
    {
        MailMessage mMailMessage = new MailMessage ();
        int lenght = to.GetLength(0);
        if (lenght > 1) {
            foreach (string email in to) {
                mMailMessage.Bcc.Add ( email );
            }
        }
        else {
            mMailMessage.To.Add ( to[0] );
        }
                mMailMessage.From = new MailAddress ("no-replay@mycompany.net");                  
                SmtpClient mSmtpClient = new SmtpClient ();
                mMailMessage.Body = message;
                mMailMessage.IsBodyHtml = true;
                mMailMessage.Priority = MailPriority.Normal;
                mMailMessage.Subject = subject;
                mSmtpClient.EnableSsl = true;                
                ServicePointManager.ServerCertificateValidationCallback = delegate(object s,X509Certificate certificate,X509Chain chain, SslPolicyErrors sslPolicyErrors) {return true;};                    
            try {  
                mSmtpClient.Send (mMailMessage);                
        }
        catch (SmtpFailedRecipientsException ex){
            for (int i = 0; i < ex.InnerExceptions.Length; i++)
            {
                SmtpStatusCode status = ex.InnerExceptions[i].StatusCode;
                if (status == SmtpStatusCode.MailboxBusy ||
                    status == SmtpStatusCode.MailboxUnavailable)
                {
                    Logger.Debug("Delivery failed - retrying in 5 seconds.");
                    System.Threading.Thread.Sleep(5000);
                    //client.Send(message);
                    mSmtpClient.Send (mMailMessage);
                }
                else
                {
                    Logger.Debug (string.Format ("Failed to deliver message to {0},{1}", ex.InnerExceptions[i].FailedRecipient, i));
                }
            }
        }
        catch (Exception ex)
        {
            Logger.Debug (string.Format("Exception caught in RetryIfBusy(): {0}", ex.ToString() ));
        }
    }

看起来您正在使用的SMTP服务器拒绝有超过100个收件人的邮件。

你可以:

使用分发列表而不是直接向每个收件人发送消息
发送不超过100个收件人的多条消息
通知服务器管理员更改限制

但是请注意，当您向数百个外部收件人发送消息时，垃圾邮件过滤器可能会将它们标记为垃圾邮件。

我在一个Microsoft文档中发现异常处理如下:

 var client = new System.Net.Mail.SmtpClient();
        try
        {
            client.Send(mailMessage);
        }
        catch (SmtpFailedRecipientsException ex)
        {
            for (int i = 0; i < ex.InnerExceptions.Length; i++)
            {
                SmtpStatusCode status = ex.InnerExceptions[i].StatusCode;
                if (status == SmtpStatusCode.MailboxBusy ||
                    status == SmtpStatusCode.MailboxUnavailable)
                {
                    Console.WriteLine("Delivery failed - retrying in 5 seconds.");
                    System.Threading.Thread.Sleep(5000);
                    client.Send(mailMessage);
                }
                else
                {
                    Console.WriteLine("Failed to deliver message to {0}",
                        ex.InnerExceptions[i].FailedRecipient);
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("Exception caught in RetryIfBusy(): {0}",
                    ex.ToString());
        }

但是我不知道如何为这个异常生成异常场景Microsoft link - for mode details