项目要引入mail.jar包。发送文字邮件没什么可具体说的，直接看Demo。有两种方式实现，一种支持html，另一种不支持。还简单实现了添加图片附件。比较复杂的是接收邮件，特别是QQ邮箱，由于腾讯邮箱的安全机制，必须在QQ邮箱内设置开启STMP、POP等协议权限，过后会研究实现这个功能，再作补充

import java.io.IOException;import java.util.Properties;import javax.mail.Authenticator;import javax.mail.BodyPart;import javax.mail.Folder;import javax.mail.Message;import javax.mail.MessagingException;import javax.mail.Multipart;import javax.mail.PasswordAuthentication;import javax.mail.Session;import javax.mail.Store;import javax.mail.Transport;import javax.mail.internet.InternetAddress;import javax.mail.internet.MimeBodyPart;import javax.mail.internet.MimeMessage;import javax.mail.internet.MimeMessage.RecipientType;import javax.mail.internet.MimeMultipart;public class SendMailDemo {		public static void main(String[] args) throws MessagingException, IOException {						/* ****************      发送邮件        *************** */		final Properties properties = System.getProperties();		properties.put("mail.smtp.auth", "true");		properties.put("mail.smtp.host", "smtp.126.com");//host的协议根据自己的邮箱决定		properties.put("mail.user", "邮箱帐号@126.com");		properties.put("mail.password", "邮箱密码");				//认证信息		Authenticator authenticator = new Authenticator() {			@Override			protected PasswordAuthentication getPasswordAuthentication(){				String account = properties.getProperty("mail.user");				String password = properties.getProperty("mail.password");				return new PasswordAuthentication(account, password);			}		};				//获取邮件session		Session session = Session.getInstance(properties, authenticator);		MimeMessage mimeMessage = new MimeMessage(session);				//发送人		InternetAddress from = new InternetAddress(properties.getProperty("mail.user"));		mimeMessage.setFrom(from);		//接收人		InternetAddress accept = new InternetAddress("接收邮箱帐号@qq.com");		/**		 * Type参数说明		 * Message.RecipientType.TO 收件人		 * Message.RecipientType.CC 抄送		 * Message.RecipientType.BCC 密送		 */		mimeMessage.setRecipient(RecipientType.BCC, accept);		//主题		mimeMessage.setSubject("this is a test mail to Lin");				//设置正文方式一：直接添加，支持html		//mimeMessage.setContent("请访问我们的官网", "text/html;charset=utf-8");				//设置正文方式二：multipart，支持但是不支持html（可添加附件）		Multipart multipart = new MimeMultipart();				BodyPart messageBodyPart = new MimeBodyPart();		messageBodyPart.setText("请访问我们的官网");		multipart.addBodyPart(messageBodyPart);				//添加附件		/*messageBodyPart = new MimeBodyPart();		String filename = "G:/MyImages/海贼王5.jpeg";		DataSource source = new FileDataSource(filename);		messageBodyPart.setDataHandler(new DataHandler(source));		messageBodyPart.setFileName(filename);		multipart.addBodyPart(messageBodyPart);*/		mimeMessage.setContent(multipart);		//发送邮件		Transport.send(mimeMessage);						/* ****************      接收邮件        *************** */		final Properties recevieprop = System.getProperties();		recevieprop.put("mail.pop3.host", "pop.126.com");		recevieprop.put("mail.user", "邮箱帐号@126.com");		recevieprop.put("mail.password", "邮箱密码");		//recevieprop.put("mail.pop3.ssl.enable", "true");//QQ邮箱需要设置ssl				Store store = session.getStore("pop3");		store.connect(recevieprop.getProperty("mail.pop3.host"), recevieprop.getProperty("mail.user"), recevieprop.getProperty("mail.password"));				Folder folder = store.getFolder("INBOX");		folder.open(Folder.READ_ONLY);   		//int size = folder.getMessageCount();		Message[] messages = folder.getMessages();		System.out.println(messages.length);	}}