在前麵的章節查詢電子郵件和讀取電子郵件，我們通過授權憑證（用戶名和密碼）以及主機，連接到您的郵箱中存儲時。相反，我們可以配置屬性有主機，並告訴您的自定義的Authenticator實例的會話。這示於下麵的例子：

創建Java類

我們將修改CheckingMails.java 請先閱讀 章查詢電子郵件 這章。其內容如下所述：

package com.yiibai;

import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.NoSuchProviderException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Store;

public class CheckingMails {

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

      // create properties field
      Properties properties = new Properties();

      properties.put("mail.pop3s.host", host);
      properties.put("mail.pop3s.port", "995");
      properties.put("mail.pop3s.starttls.enable", "true");

      // Setup authentication, get session
      Session emailSession = Session.getInstance(properties,
         new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
               return new PasswordAuthentication(
                  "manishapatil3may@gmail.com", "manisha123");
            }
         });
      // emailSession.setDebug(true);

      // create the POP3 store object and connect with the pop server
      Store store = emailSession.getStore("pop3s");

      store.connect();

      // 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.getMessages();
      System.out.println("messages.length---" + messages.length);

      for (int i = 0, n = messages.length; i < n; i++) {
         Message message = messages[i];
         System.out.println("---------------------------------");
         System.out.println("Email Number " + (i + 1));
         System.out.println("Subject: " + message.getSubject());
         System.out.println("From: " + message.getFrom()[0]);
         System.out.println("Text: " + message.getContent().toString());
      }

      // 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 = "pop.gmail.com";// change accordingly
      String mailStoreType = "pop3";
      String username = "abc@gmail.com";// change accordingly
      String password = "*****";// change accordingly

      check(host, mailStoreType, username, password);

   }

}

您可以通過取消注釋語句上設置調試emailSession.setDebug(true);

編譯並運行

現在，我們班是準備好了，讓我們編譯上麵的類。我已經保存了類CheckingMails.java目錄： /home/manisha/JavaMailAPIExercise. 我們需要 javax.mail.jar andactivation.jar 在classpath中。執行下麵的命令從命令提示符編譯類（兩個罐子被放置在 /home/manisha/ 目錄下）：

javac -cp /home/manisha/activation.jar:/home/manisha/javax.mail.jar: CheckingMails.java

現在，這個類被編譯，執行下麵的命令來運行：

java -cp /home/manisha/activation.jar:/home/manisha/javax.mail.jar: CheckingMails

驗證輸出

你可以看到一個類似的消息，如下命令控製台上：

messages.length---3
---------------------------------
Email Number 1
Subject: Today is a nice day
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@45f676cb
---------------------------------
Email Number 2
Subject: hiiii....
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@37f12d4f
---------------------------------
Email Number 3
Subject: helloo
From: XYZ <xyz@gmail.com>
Text: javax.mail.internet.MimeMultipart@3ad5ba3a