Android 使用javaMail jar包发送邮件到指定邮箱，并可以发送图片附件

          Android发送邮件到指定邮箱一种是调用系统发邮件的软件，可以添加邮箱账号就可以发送邮件；第二种是使用javamail来发送邮件，使用javamail来发送邮件需要使用javaMail的jar包 mail.jar 、additionnal.jar 、activation.jar 这三个包 。关键代码如下：

import java.io.File;
import java.util.Date;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

/**
 * Created by Ryan on 2017/12/10.
 */
public class EmailSender {

    private Properties properties;
    private Session session;
    private Message message;
    private MimeMultipart multipart;

    public EmailSender() {
        super();
        this.properties = new Properties();
    }
    public void setProperties(String host,String post){
        //地址
        this.properties.put("mail.smtp.host",host);
        //端口号
        this.properties.put("mail.smtp.post",post);
        //是否验证
        this.properties.put("mail.smtp.auth",true);
        this.session= Session.getInstance(properties);
        this.message = new MimeMessage(session);
        this.multipart = new MimeMultipart("mixed");
    }
    /**
     * 设置收件人
     * @param receiver
     * @throws MessagingException
     */
    public void setReceiver(String[] receiver) throws MessagingException{
        javax.mail.Address[] address = new InternetAddress[receiver.length];
        for(int i=0;ilength;i++){
            address[i] = new InternetAddress(receiver[i]);
        }
        this.message.setRecipients(Message.RecipientType.TO, address);
    }
    /**
     * 设置邮件
     * @param from 来源
     * @param title 标题
     * @param content 内容
     * @throws AddressException
     * @throws MessagingException
     */
    public void setMessage(String from,String title,String content) throws AddressException, MessagingException{
        this.message.setFrom(new InternetAddress(from));
        this.message.setSubject(title);
        //纯文本的话用setText()就行，不过有附件就显示不出来内容了
        MimeBodyPart textBody = new MimeBodyPart();
        textBody.setContent(content,"text/html;charset=gbk");
        this.multipart.addBodyPart(textBody);
    }
    /**
     * 添加附件
     * @param filePath 文件路径
     * @throws MessagingException
     */
    public void addAttachment(String filePath) throws MessagingException {
        FileDataSource fileDataSource = new FileDataSource(new File(filePath));
        DataHandler dataHandler = new DataHandler(fileDataSource);
        MimeBodyPart mimeBodyPart = new MimeBodyPart();
        mimeBodyPart.setDataHandler(dataHandler);
        mimeBodyPart.setFileName(fileDataSource.getName());
        this.multipart.addBodyPart(mimeBodyPart);
    }
    /**
     * 发送邮件
     * @param host 地址
     * @param account 账户名
     * @param pwd 密码
     * @throws MessagingException
     */
    public void sendEmail(String host,String account,String pwd) throws MessagingException{
        //发送时间
        this.message.setSentDate(new Date());
        //发送的内容，文本和附件
        this.message.setContent(this.multipart);
        this.message.saveChanges();
        //创建邮件发送对象，并指定其使用SMTP协议发送邮件
        Transport transport=session.getTransport("smtp");
        //登录邮箱
        transport.connect(host,account,pwd);
        //发送邮件
        transport.sendMessage(message, message.getAllRecipients());
        //关闭连接
        transport.close();
    }
}

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import java.io.File;

import javax.mail.MessagingException;
import javax.mail.internet.AddressException;

public class SendMailActivity extends Activity {


    private Button btnSend = null;

    private static final String TAG = "SendMailActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_send_mail);
        btnSend = (Button) findViewById(R.id.btnSend);
        btnSend.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //耗时操作要起线程...有几个新手都是这个问题
                new Thread(new Runnable() {

                    @Override
                    public void run() {
                        try {
                            EmailSender sender = new EmailSender();
                            //设置服务器地址和端口，网上搜的到
                            sender.setProperties("smtp.163.com", "25");
                            //分别设置发件人，邮件标题和文本内容
                            sender.setMessage("[email protected]", "This is title", "This is content！");
                            //设置收件人的邮箱

                            sender.setReceiver(new String[]{"[email protected]"});
                            File file = new File("/sdcard/DCIM/Camera/IMG_20150917_141427.jpg");
                            if(file.exists()) {
                                Log.d(TAG,"file.exists()------>>>>>>");
                                //添加附件
                                //这个附件的路径是我手机里的啊，要发你得换成你手机里正确的路径
                                sender.addAttachment("/sdcard/DCIM/Camera/IMG_20150917_141427.jpg");

                            } else {
                                Log.d(TAG,"file.notexists()------>>>>>>");
                            }

                            //发送邮件,sender.setMessage("你的163邮箱账号", "EmailS//ender", "Java Mail ！");这里面两个邮箱账号要一致
                            sender.sendEmail("smtp.163.com", "[email protected]", "password");

                        } catch (AddressException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        } catch (MessagingException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                }).start();
            }
        });
    }
}

源码下载地址：https://github.com/Ryan-HANG/EMailSend.git