如何在C#中处理来自Exchange Server的NDR电子邮件？

Question

目前，我的应用程序有能力处理传入的电子邮件，如果它与代码中给定的标准不匹配，则会退回。但是，我想添加另一种类型的电子邮件进行处理，这些电子邮件是来自Microsoft Exchange Server的NDR“未送达报告”。因此我应用程序不会响应/退回到exchange服务器的NDR，这会导致我的邮箱和Exchange Server之间的循环。下面的方法在无效时触发

private static void ProcessInvidMsgWithoutNo(string sMsgFrom, string sFromEmail, EmailMsg sMsgReceived, EmailMessage message)
    {
        EmailMsg.MoveToInvalid(message);

        sMsgReceived.IsValid = false;
        SaveMsgReceived(sMsgReceived, 0, string.Empty);

        if (!sFromEmail.Equals(string.Empty))
        {
            ResponseForInvidMsg(sFromEmail);
        }
        else
        {
            curLog.WriteLog(string.Format(CultureInfo.CurrentCulture, MsgEMChecker27, sMsgFrom));
        }
    }

下面的方法触发响应传入的无效消息，如上所述。

private static void ResponseForInvidMsg(string sFromEmail)
    {
        string tErrSubjectMsg = String.Format(CultureInfo.CurrentCulture, "{0}\\Resource\\MsgErrorSubjectAck.html", Entity.GetSetting("DocRootDir"));

        StringBuilder htmlText = new StringBuilder();
        FileStream fsFile = new FileStream(tErrSubjectMsg, FileMode.Open);

        if (fsFile != null)
        {
            StreamReader reader = new StreamReader(fsFile, Encoding.Default);

            string text;
            do
            {
                text = reader.ReadLine();
                if ((text != null) && (text != ""))
                    htmlText.Append(text + "\n");
            } while (text != null);

            reader.Close();
            fsFile.Close();
            fsFile = null;
        }
        else
            htmlText.Append("hello");

        string tToCustomerSubject = ReplyForInvalid;
        string tMessage = htmlText.ToString();

        EmailMsg emTo = new EmailMsg(string.Empty, sFromEmail, tToCustomerSubject, tMessage);
        emTo.MsgType = EmailMsg.TypeSentCustomer;
        emTo.Send(false); //Not save but CC to generic email box
    }

请帮助我找到一种停止代码以响应Exchange Server NDR的方法。谢谢

Answer 1

开始的地方应该是检查消息的ItemClass请参见https://docs.microsoft.com/en-us/openspecs/exchange_server_protocols/ms-asemail/51d84da6-a2da-41e9-8ca7-eb6c4e72c28d。NDR、交付报告等应以报告为前缀，例如

REPORT.IPM.NOTE.NDR Non-delivery report for a standard message.
REPORT.IPM.NOTE.DR Delivery receipt for a standard message.