重定向退回的邮件，并从退回的邮件中读取附加的文件名

Question

我有 2 个程序，一个用于发送邮件，另一个用于阅读邮件。我的第一个问题是如何将退回的邮件重定向到用户以外的电子邮件 ID。第二个问题是如果我有一封退回的邮件，我如何阅读附件的名称。我经历了很多帖子，但似乎没有任何效果。任何帮助表示赞赏。

用于发送邮件的代码

import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class bounceMail {
    String host, port, emailid,username, password;
    Properties props = System.getProperties();
    Session l_session = null;
    Session l_session1= null;

    public void sendMessage(String toEmail, String subject, String msg) {
        host = "smtp.mail.yahoo.com";
        port = "465";

        emailid = "fromemailid";
        username = "fromusername";
        password = "******";

        props.put("mail.smtp.host", host);
        props.put("mail.smtp.auth", "true");
        //props.put("mail.debug", "true");
        props.put("mail.smtp.port", port);
        props.put("mail.smtp.starttls.enable","true");
        props.put("mail.smtp.socketFactory.port", port);
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");
        //props.put("mail.smtp.from", "bounceemailid"); // not working
        l_session = Session.getInstance(props,
                new javax.mail.Authenticator() {
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication(username, password);
                    }
                });
        //l_session.setDebug(true); // Enable the debug mode

        try {
            MimeMessage message = new MimeMessage(l_session);

            //message.addFrom(InternetAddress.parse("bounceemail@yahoo.com")); // not working
            //message.setReplyTo(InternetAddress.parse("bounceemail@yahoo.com")); // not working
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(toEmail));
            message.setSubject(subject);
            message.setContent(msg, "text/html");
            Transport.send(message);
            System.out.println("Message Sent");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    static public void main(String args[]){
        bounceMail b = new bounceMail();
        b.sendMessage("junkemailid","Test","test Mail");
    }

}

用于阅读邮件的代码

import java.util.Properties;

import javax.mail.Flags;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.NoSuchProviderException;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.search.FlagTerm;



public class CheckingMail {

  public static void check(String host, String storeType, String user,
  String password) 
  {
    try {

    //create properties field
    Properties properties = new Properties();
    properties.put("mail.imap.host", host);
    properties.put("mail.imap.port", "993");
    properties.put("mail.imap.starttls.enable", "true");
    Session emailSession = Session.getDefaultInstance(properties);


    Store store = emailSession.getStore("imaps");
    store.connect(host, user, password);

    //create the folder object and open it
    Folder emailFolder = store.getFolder("INBOX");
    emailFolder.open(Folder.READ_ONLY);

    // retrieve the messages from the folder in an array and print it
    Message[] messages = emailFolder.search(new FlagTerm(new Flags(Flags.Flag.SEEN), false)); 
    System.out.println("messages.length---" + messages.length);
    int bcnt = 0;
    for (int i = 0, n = messages.length; i < n; i++) {
       Message message = messages[i];
       if(message.getFrom()[0].toString().contains("MAILER-DAEMON")){
         bcnt++;
       }
       System.out.println("---------------------------------");
       System.out.println("Email Number " + (i + 1));
       System.out.println("Subject: " + message.getSubject());
       System.out.println("From: " + message.getFrom()[0]);

       Object content = message.getContent();
       if (content instanceof String)
           System.out.println("String");        

       if (content instanceof Multipart) {
           Multipart multipart = (Multipart) content;
           for (int j = 0; j < multipart.getCount(); j++) {
              System.out.println(multipart.getBodyPart(j).getFileName());
           }
       }

       for(int j=0;j<message.getAllRecipients().length; j++){
           System.out.println("Recipients "+j+" : " + message.getAllRecipients()[j]);
       }
       System.out.println("Date: " + message.getSentDate());
    }
    System.out.println("Bounce count : " + bcnt);

    //close the store and folder objects
    emailFolder.close(false);
    store.close();

    } catch (NoSuchProviderException e) {
       e.printStackTrace();
    } catch (MessagingException e) {
       e.printStackTrace();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  public static void main(String[] args) {
     String host = "imap.mail.yahoo.com";
     String mailStoreType = "imap";
     String username = "emailid";
     String password = "*****";
     check(host, mailStoreType, username, password);

  }

}

是否可以在发送邮件时设置自己的标题或属性，以便在邮件退回时读取？

Answer 1

你读过this JavaMail FAQ entry吗？

您可以通过设置“mail.smtp.from”属性来设置用于返回失败消息的 SMTP“信封发件人”地址，如 javadocs for the com.sun.mail.smtp package 中所述。

Answer 2

回答第二个问题。我可以使用以下方法从退回的邮件中读取附件的名称（需要更好的方法）

BufferedReader reader = new BufferedReader(new StringReader(message.getContent().toString()));
while ((str = reader.readLine()) != null)  {
    index = str.indexOf("filename");
    if(index >-1){
        filename = str.substring(index+9); // 9 characters -> "filename=" 
        if (filename.length() > 0) System.out.println("Attachment  : " + filename);
    }
}