JavaMail Management explains how to manage folders, quota, bounced message in the JavaMail API. Generally JavaMail API involves to send, receive, compose an email by making use of Java program.The JavaMail API management invoves size, limit, listing, delete the mails based on name or number to reduce the complexity. Have to know where the message is stored in inbox or any other folder. Here discussing about some management techniques involved in JavaMail API. 

Above figure shows managing the simple JavaMail from sender’s to recipients.

Generally bouncing of message will occur, but RFC 1211 gives more information on error reports. The particular existence username is determined only by the server, The server will returns the message indicates that the failure of sending message to sender with its original message only when server detects an error.

To correlate the error message with original message and sending notification to sender is difficult and causes problem. For delivery status notifications the JavaMail API supports for resolve it. There are some techniques and heuristics for to overcome with this problem. One of the technique to set the return path in envelope. The java.mail.smtp.from represents the address where the bounced mails are sent and explained below with example in detail.

package firstmail;
import java.util.Properties;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
public class bouncedmails {
   public static void main(String[] args) throws Exception {
      String smtpServer = "smtp.gmail.com";
      int port = 465;
      final String userid = "9saireddy@gmail.com";//change accordingly
      final String password = "splesson";//change accordingly
      String contentType = "text/html";
      String subject = "test: bounce an email to a different address " +
				"from the sender";
      String from = "9saireddy@gmail.com";
      String to = "bouncer@fauxmail.com";//some invalid address
      String bounceAddr = "9saireddy@gmail.com";//change accordingly
      String body = "Test: get message to bounce to a separate email address";
      Properties props = new Properties();
      props.put("mail.smtp.auth", "true");
      props.put("mail.smtp.starttls.enable", "true");
      props.put("mail.smtp.host", smtpServer);
      props.put("mail.smtp.port", "465");
      props.put("mail.transport.protocol", "smtp");
      props.put("mail.smtp.from", bounceAddr);
      Session mailSession = Session.getInstance(props,
         new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
               return new PasswordAuthentication(userid, password);
            }
         });
      MimeMessage message = new MimeMessage(mailSession);
      message.addFrom(InternetAddress.parse(from));
      message.setRecipients(Message.RecipientType.TO, to);
      message.setSubject(subject);
      message.setContent(body, contentType);
      Transport transport = mailSession.getTransport();
      try {
         System.out.println("Sending ....");
         transport.connect(smtpServer, port, userid, password);
         transport.sendMessage(message,
            message.getRecipients(Message.RecipientType.TO));
         System.out.println("Sending done ...");
      } catch (Exception e) {
         System.err.println("Error Sending: ");
         e.printStackTrace();
      }
      transport.close();
   }// end function main()
}

Output

Sending ..
Sent .

The quota management involves the size, limit of messages or amount of messages in email store and quota is limited in JavaMail API. The JavaMail API calls quota to counts request of each and every mail service. There are some quota criteria, they are
Including attachments maximum size of incoming messages.
Including attachments maximum size of outgoing messages.
At the time recipient is a administrator, maximum size of the message.

Let us see the example for quota management below.

import java.util.Properties;
import javax.mail.Quota;
import javax.mail.Session;
import javax.mail.Store;
import com.sun.mail.imap.IMAPStore;
public class QuotaExample 
{
   public static void main(String[] args) 
   {
      try 
      {
         Properties properties = new Properties();
         properties.put("mail.store.protocol", "imaps");
         properties.put("mail.imaps.port", "993");
         properties.put("mail.imaps.starttls.enable", "true");
         Session emailSession = Session.getDefaultInstance(properties);
         // emailSession.setDebug(true);
         // creating the IMAP3 store object and connect with the pop server
         Store store = emailSession.getStore("imaps");
         // To change the user and password accordingly
         store.connect("imap.gmail.com", "abc@gmail.com", "*****");
         IMAPStore imapStore = (IMAPStore) store;
         System.out.println("imapStore - " + imapStore);
         // To get quota
         Quota[] quotas = imapStore.getQuota("INBOX");
         //Iterate through the Quotas
         for (Quota quota : quotas) {
            System.out.println(String.format("quotaRoot:'%s'",
               quota.quotaRoot));
            //Iterate through the Quota Resource
            for (Quota.Resource resource : quota.resources) {
               System.out.println(String.format(
                  "name:'%s', limit:'%s', usage:'%s'", resource.name,
                  resource.limit, resource.usage));
            }
         }
      } catch (Exception e) 
      {
         e.printStackTrace();
      }
   }
} 

Output

imapStore -imaps://abc%40gmail.com@imap.gmail.com
quotaRoot:''
name:'STORAGE', limit:'15728640', usage:'513'

After getting the store object then have to fetch quota array and iterate it, print it. Here imap.gmail.com server is used for implementation of QuotaAwareStore by IMAPStore.

Folder class is an abstract class to specify the folder for mail messages. To get the folder only after store connection is possible. And the messages actually stored in folder. The folder class is declared as shown below
public abstract Class Folder extends Object

The function of this class have to declare the methods for deleting, searching for folder, listing messages in folder and requests named folders from the server. By using protected constructor have to create directly a folder. From session, store also have to get folder by using getFolder() method.
public abstract Folder getFolder(String name) throws MessagingException

• JavaMail Management – Managing the bounced Mails.
• JavaMail Management – Managing the quota in JavaMail API.
• JavaMail Management – Managing the folder to store and retrieve the messages, to avoid correlation of messages.
• JavaMail Management – Generally bouncing of message will occur, but RFC 1211 gives more information on error reports.
• JavaMail Management – The quota management involves the size, limit of messages or amount of messages in email store and quota is limited in JavaMail API.