Question

我正在尝试使用Java发送电子邮件：

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;

public class SendEmail {

   public static void main(String [] args) {

      // Recipient's email ID needs to be mentioned.
      String to = "abcd@gmail.com";

      // Sender's email ID needs to be mentioned
      String from = "web@gmail.com";

      // Assuming you are sending email from localhost
      String host = "localhost";

      // Get system properties
      Properties properties = System.getProperties();

      // Setup mail server
      properties.setProperty("mail.smtp.host", host);

      // Get the default Session object.
      Session session = Session.getDefaultInstance(properties);

      try{
         // Create a default MimeMessage object.
         MimeMessage message = new MimeMessage(session);

         // Set From: header field of the header.
         message.setFrom(new InternetAddress(from));

         // Set To: header field of the header.
         message.addRecipient(Message.RecipientType.TO,
                                  new InternetAddress(to));

         // Set Subject: header field
         message.setSubject("This is the Subject Line!");

         // Now set the actual message
         message.setText("This is actual message");

         // Send message
         Transport.send(message);
         System.out.println("Sent message successfully....");
      }catch (MessagingException mex) {
         mex.printStackTrace();
      }
   }
}

我收到错误：

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
  nested exception is:java.net.ConnectException: Connection refused: connect
        at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1706)
        at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)

此代码是否可以发送电子邮件？

Answer 1

以下代码适用于Google SMTP服务器。您需要提供Google用户名和密码。

import com.sun.mail.smtp.SMTPTransport;
import java.security.Security;
import java.util.Date;
import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

/**
 *
 * @author doraemon
 */
public class GoogleMail {
    private GoogleMail() {
    }

    /**
     * Send email using GMail SMTP server.
     *
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param title title of the message
     * @param message message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
     */
    public static void Send(final String username, final String password, String recipientEmail, String title, String message) throws AddressException, MessagingException {
        GoogleMail.Send(username, password, recipientEmail, "", title, message);
    }

    /**
     * Send email using GMail SMTP server.
     *
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param ccEmail CC recipient. Can be empty if there is no CC recipient
     * @param title title of the message
     * @param message message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
     */
    public static void Send(final String username, final String password, String recipientEmail, String ccEmail, String title, String message) throws AddressException, MessagingException {
        Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
        final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";

        // Get a Properties object
        Properties props = System.getProperties();
        props.setProperty("mail.smtps.host", "smtp.gmail.com");
        props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
        props.setProperty("mail.smtp.socketFactory.fallback", "false");
        props.setProperty("mail.smtp.port", "465");
        props.setProperty("mail.smtp.socketFactory.port", "465");
        props.setProperty("mail.smtps.auth", "true");

        /*
        If set to false, the QUIT command is sent and the connection is immediately closed. If set 
        to true (the default), causes the transport to wait for the response to the QUIT command.

        ref :   http://java.sun.com/products/javamail/javadocs/com/sun/mail/smtp/package-summary.html
                http://forum.java.sun.com/thread.jspa?threadID=5205249
                smtpsend.java - demo program from javamail
        */
        props.put("mail.smtps.quitwait", "false");

        Session session = Session.getInstance(props, null);

        // -- Create a new message --
        final MimeMessage msg = new MimeMessage(session);

        // -- Set the FROM and TO fields --
        msg.setFrom(new InternetAddress(username + "@gmail.com"));
        msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail, false));

        if (ccEmail.length() > 0) {
            msg.setRecipients(Message.RecipientType.CC, InternetAddress.parse(ccEmail, false));
        }

        msg.setSubject(title);
        msg.setText(message, "utf-8");
        msg.setSentDate(new Date());

        SMTPTransport t = (SMTPTransport)session.getTransport("smtps");

        t.connect("smtp.gmail.com", username, password);
        t.sendMessage(msg, msg.getAllRecipients());      
        t.close();
    }
}

2015年12月11日更新

用户名+密码不再是推荐的解决方案。这是由于

我试过这个，Gmail在此代码中发送了用作用户名的电子邮件电子邮件说我们最近阻止了对您的Google的登录尝试帐户，并指导我到这个支持页面： support.google.com/accounts/answer/6010255所以它寻找它的工作，用于发送的电子邮件帐户需要减少自己的安全

Google发布了Gmail API - https://developers.google.com/gmail/api/?hl=en。我们应该使用oAuth2方法，而不是用户名+密码。

以下是使用Gmail API的代码段。

GoogleMail.java

import com.google.api.client.util.Base64;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.model.Message;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Properties;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

/**
 *
 * @author doraemon
 */
public class GoogleMail {
    private GoogleMail() {
    }

    private static MimeMessage createEmail(String to, String cc, String from, String subject, String bodyText) throws MessagingException {
        Properties props = new Properties();
        Session session = Session.getDefaultInstance(props, null);

        MimeMessage email = new MimeMessage(session);
        InternetAddress tAddress = new InternetAddress(to);
        InternetAddress cAddress = cc.isEmpty() ? null : new InternetAddress(cc);
        InternetAddress fAddress = new InternetAddress(from);

        email.setFrom(fAddress);
        if (cAddress != null) {
            email.addRecipient(javax.mail.Message.RecipientType.CC, cAddress);
        }
        email.addRecipient(javax.mail.Message.RecipientType.TO, tAddress);
        email.setSubject(subject);
        email.setText(bodyText);
        return email;
    }

    private static Message createMessageWithEmail(MimeMessage email) throws MessagingException, IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        email.writeTo(baos);
        String encodedEmail = Base64.encodeBase64URLSafeString(baos.toByteArray());
        Message message = new Message();
        message.setRaw(encodedEmail);
        return message;
    }

    public static void Send(Gmail service, String recipientEmail, String ccEmail, String fromEmail, String title, String message) throws IOException, MessagingException {
        Message m = createMessageWithEmail(createEmail(recipientEmail, ccEmail, fromEmail, title, message));
        service.users().messages().send("me", m).execute();
    }
}

要通过oAuth2构建授权的Gmail服务，请参阅以下代码段。

Utils.java

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.GmailScopes;
import com.google.api.services.oauth2.Oauth2;
import com.google.api.services.oauth2.model.Userinfoplus;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.GeneralSecurityException;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.yccheok.jstock.engine.Pair;

/**
 *
 * @author yccheok
 */
public class Utils {
    /** Global instance of the JSON factory. */
    private static final GsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();

    /** Global instance of the HTTP transport. */
    private static HttpTransport httpTransport;

    private static final Log log = LogFactory.getLog(Utils.class);

    static {
        try {
            // initialize the transport
            httpTransport = GoogleNetHttpTransport.newTrustedTransport();

        } catch (IOException ex) {
            log.error(null, ex);
        } catch (GeneralSecurityException ex) {
            log.error(null, ex);
        }
    }

    private static File getGmailDataDirectory() {
        return new File(org.yccheok.jstock.gui.Utils.getUserDataDirectory() + "authentication" + File.separator + "gmail");
    }

    /**
     * Send a request to the UserInfo API to retrieve the user's information.
     *
     * @param credentials OAuth 2.0 credentials to authorize the request.
     * @return User's information.
     * @throws java.io.IOException
     */
    public static Userinfoplus getUserInfo(Credential credentials) throws IOException
    {
        Oauth2 userInfoService =
            new Oauth2.Builder(httpTransport, JSON_FACTORY, credentials).setApplicationName("JStock").build();
        Userinfoplus userInfo  = userInfoService.userinfo().get().execute();
        return userInfo;
    }

    public static String loadEmail(File dataStoreDirectory)  {
        File file = new File(dataStoreDirectory, "email");
        try {
            return new String(Files.readAllBytes(Paths.get(file.toURI())), "UTF-8");
        } catch (IOException ex) {
            log.error(null, ex);
            return null;
        }
    }

    public static boolean saveEmail(File dataStoreDirectory, String email) {
        File file = new File(dataStoreDirectory, "email");
        try {
            //If the constructor throws an exception, the finally block will NOT execute
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), "UTF-8"));
            try {
                writer.write(email);
            } finally {
                writer.close();
            }
            return true;
        } catch (IOException ex){
            log.error(null, ex);
            return false;
        }
    }

    public static void logoutGmail() {
        File credential = new File(getGmailDataDirectory(), "StoredCredential");
        File email = new File(getGmailDataDirectory(), "email");
        credential.delete();
        email.delete();
    }

    public static Pair<Pair<Credential, String>, Boolean> authorizeGmail() throws Exception {
        // Ask for only the permissions you need. Asking for more permissions will
        // reduce the number of users who finish the process for giving you access
        // to their accounts. It will also increase the amount of effort you will
        // have to spend explaining to users what you are doing with their data.
        // Here we are listing all of the available scopes. You should remove scopes
        // that you are not actually using.
        Set<String> scopes = new HashSet<>();

        // We would like to display what email this credential associated to.
        scopes.add("email");

        scopes.add(GmailScopes.GMAIL_SEND);

        // load client secrets
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(Utils.JSON_FACTORY,
            new InputStreamReader(Utils.class.getResourceAsStream("/assets/authentication/gmail/client_secrets.json")));

        return authorize(clientSecrets, scopes, getGmailDataDirectory());
    }

    /** Authorizes the installed application to access user's protected data.
     * @return 
     * @throws java.lang.Exception */
    private static Pair<Pair<Credential, String>, Boolean> authorize(GoogleClientSecrets clientSecrets, Set<String> scopes, File dataStoreDirectory) throws Exception {
        // Set up authorization code flow.

        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            httpTransport, JSON_FACTORY, clientSecrets, scopes)
            .setDataStoreFactory(new FileDataStoreFactory(dataStoreDirectory))
            .build();
        // authorize
        return new MyAuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    }

    public static Gmail getGmail(Credential credential) {
        Gmail service = new Gmail.Builder(httpTransport, JSON_FACTORY, credential).setApplicationName("JStock").build();
        return service;        
    }
}

为了提供用户友好的oAuth2身份验证方式，我利用JavaFX，显示以下输入对话框

可在MyAuthorizationCodeInstalledApp.java和SimpleSwingBrowser.java

中找到显示用户友好型oAuth2对话框的键

Answer 2

以下代码为我工作。

import java.io.UnsupportedEncodingException;
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.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;


public class SendMail {

    public static void main(String[] args) {

        final String username = "your_user_name@gmail.com";
        final String password = "yourpassword";

        Properties props = new Properties();
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "587");

        Session session = Session.getInstance(props,
          new javax.mail.Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(username, password);
            }
          });

        try {

            Message message = new MimeMessage(session);
            message.setFrom(new InternetAddress("your_user_name@gmail.com"));
            message.setRecipients(Message.RecipientType.TO,
                InternetAddress.parse("to_email_address@domain.com"));
            message.setSubject("Testing Subject");
            message.setText("Dear Mail Crawler,"
                + "\n\n No spam to my email, please!");

            Transport.send(message);

            System.out.println("Done");

        } catch (MessagingException e) {
            throw new RuntimeException(e);
        }
    }
}

Answer 3

import java.util.Date;
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 SendEmail extends Object{

public static void main(String [] args)
{

    try{

        Properties props = new Properties();
        props.put("mail.smtp.host", "smtp.mail.yahoo.com"); // for gmail use smtp.gmail.com
        props.put("mail.smtp.auth", "true");
        props.put("mail.debug", "true"); 
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.port", "465");
        props.put("mail.smtp.socketFactory.port", "465");
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");

        Session mailSession = Session.getInstance(props, new javax.mail.Authenticator() {

            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("username@yahoo.com", "password");
            }
        });

        mailSession.setDebug(true); // Enable the debug mode

        Message msg = new MimeMessage( mailSession );

        //--[ Set the FROM, TO, DATE and SUBJECT fields
        msg.setFrom( new InternetAddress( "fromusername@yahoo.com" ) );
        msg.setRecipients( Message.RecipientType.TO,InternetAddress.parse("tousername@gmail.com") );
        msg.setSentDate( new Date());
        msg.setSubject( "Hello World!" );

        //--[ Create the body of the mail
        msg.setText( "Hello from my first e-mail sent with JavaMail" );

        //--[ Ask the Transport class to send our mail message
        Transport.send( msg );

    }catch(Exception E){
        System.out.println( "Oops something has gone pearshaped!");
        System.out.println( E );
    }
}
}

必需的jar文件

Click here - How to add External Jars

Answer 4

简短回答 - 否。

答案很长 - 不，因为代码依赖于本地计算机上运行的SMTP服务器的存在，并且侦听端口25. SMTP服务器（技术上是MTA或邮件传输代理）负责与邮件用户代理（MUA，在本例中是Java进程）接收外发电子邮件。

现在，MTA通常负责接收来自特定域的用户的邮件。因此，对于域名gmail.com，它将是Google邮件服务器，负责验证邮件用户代理，从而将邮件传输到GMail服务器上的收件箱。我不确定GMail是否信任开放邮件中继服务器，但代表Google进行身份验证并将邮件中继到GMail服务器当然不是一件容易的事。

如果您阅读JavaMail FAQ on using JavaMail to accessing GMail，您会注意到主机名和端口恰好指向GMail服务器，当然不是指向localhost。如果您打算使用本地计算机，则需要执行中继或转发。

如果您希望在SMTP方面获得任何目标，则可能需要深入了解SMTP协议。您可以从Wikipedia article on SMTP开始，但任何进一步的进展实际上都需要针对SMTP服务器进行编程。

Answer 5

您需要SMTP服务器才能发送邮件。您可以在自己的PC上本地安装服务器，也可以使用众多在线服务器之一。其中一个比较知名的服务器是谷歌：

我刚刚使用Google SMTP configurations中的第一个示例成功测试了允许的Simple Java Mail：

    final Email email = EmailBuilder.startingBlank()
        .from("lollypop", "lol.pop@somemail.com")
        .to("C.Cane", "candycane@candyshop.org")
        .withPlainText("We should meet up!")
        .withHTMLText("<b>We should meet up!</b>")
        .withSubject("hey");

    // starting 5.0.0 do the following using the MailerBuilder instead...
    new Mailer("smtp.gmail.com", 25, "your user", "your password", TransportStrategy.SMTP_TLS).sendMail(email);
    new Mailer("smtp.gmail.com", 587, "your user", "your password", TransportStrategy.SMTP_TLS).sendMail(email);
    new Mailer("smtp.gmail.com", 465, "your user", "your password", TransportStrategy.SMTP_SSL).sendMail(email);

请注意各种端口和传输策略（为您处理所有必需的属性）。

奇怪的是，即使Google的指示say otherwise，Google也要求在端口25上使用TLS。

Answer 6

这已经发布了很长一段时间。但截至2012年11月13日，我可以验证端口465是否仍然有效。

请参阅GaryM在this forum上的回答。我希望这可以帮助更多的人。

/*
* Created on Feb 21, 2005
*
*/

import java.security.Security;
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 GoogleTest {

    private static final String SMTP_HOST_NAME = "smtp.gmail.com";
    private static final String SMTP_PORT = "465";
    private static final String emailMsgTxt = "Test Message Contents";
    private static final String emailSubjectTxt = "A test from gmail";
    private static final String emailFromAddress = "";
    private static final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
    private static final String[] sendTo = { "" };


    public static void main(String args[]) throws Exception {

        Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());

        new GoogleTest().sendSSLMessage(sendTo, emailSubjectTxt,
            emailMsgTxt, emailFromAddress);
        System.out.println("Sucessfully mail to All Users");
    }

    public void sendSSLMessage(String recipients[], String subject,
                               String message, String from) throws MessagingException {
        boolean debug = true;

        Properties props = new Properties();
        props.put("mail.smtp.host", SMTP_HOST_NAME);
        props.put("mail.smtp.auth", "true");
        props.put("mail.debug", "true");
        props.put("mail.smtp.port", SMTP_PORT);
        props.put("mail.smtp.socketFactory.port", SMTP_PORT);
        props.put("mail.smtp.socketFactory.class", SSL_FACTORY);
        props.put("mail.smtp.socketFactory.fallback", "false");

        Session session = Session.getDefaultInstance(props,
            new javax.mail.Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("xxxxxx", "xxxxxx");
            }
        });

        session.setDebug(debug);

        Message msg = new MimeMessage(session);
        InternetAddress addressFrom = new InternetAddress(from);
        msg.setFrom(addressFrom);

        InternetAddress[] addressTo = new InternetAddress[recipients.length];
        for (int i = 0; i < recipients.length; i++) {
            addressTo[i] = new InternetAddress(recipients);
        }
        msg.setRecipients(Message.RecipientType.TO, addressTo);

        // Setting the Subject and Content Type
        msg.setSubject(subject);
        msg.setContent(message, "text/plain");
        Transport.send(msg);
    }
}

Answer 7

此代码是否可以发送电子邮件？

嗯，不，不是因为你收到错误而改变了一些部分。您当前正在尝试通过在localhost上运行的SMTP服务器发送邮件，但您没有运行任何ConnectException。

假设代码没问题（我没有真正检查过），您必须运行本地SMTP服务器，或者使用（远程）服务器（来自您的ISP）。

关于代码，您可以在FAQ中提到的JavaMail下载包中找到示例：

Where can I find some example programs that show how to use JavaMail?
     问：我在哪里可以找到一些例子   显示如何使用的程序   JavaMail的？
  答：有很多例子   JavaMail download package中包含的程序，包括简单程序   命令行程序说明   JavaMail API的各个方面，a   基于Swing的GUI应用程序，简单易用   基于servlet的应用程序，以及   使用JSP完成Web应用程序   页面和标签库。

Answer 8

以下代码非常有效。请尝试使用javamail-1.4.5.jar

作为java应用程序

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class MailSender
{
final String senderEmailID = "typesendermailid@gmail.com";
final String senderPassword = "typesenderpassword";
final String emailSMTPserver = "smtp.gmail.com";
final String emailServerPort = "465";
String receiverEmailID = null;
static String emailSubject = "Test Mail";
static String emailBody = ":)";
public MailSender(String receiverEmailID, String emailSubject, String emailBody)
{
this.receiverEmailID=receiverEmailID;
this.emailSubject=emailSubject;
this.emailBody=emailBody;
Properties props = new Properties();
props.put("mail.smtp.user",senderEmailID);
props.put("mail.smtp.host", emailSMTPserver);
props.put("mail.smtp.port", emailServerPort);
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.socketFactory.port", emailServerPort);
props.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
SecurityManager security = System.getSecurityManager();
try
{
Authenticator auth = new SMTPAuthenticator();
Session session = Session.getInstance(props, auth);
MimeMessage msg = new MimeMessage(session);
msg.setText(emailBody);
msg.setSubject(emailSubject);
msg.setFrom(new InternetAddress(senderEmailID));
msg.addRecipient(Message.RecipientType.TO,
new InternetAddress(receiverEmailID));
Transport.send(msg);
System.out.println("Message send Successfully:)");
}
catch (Exception mex)
{
mex.printStackTrace();
}
}
public class SMTPAuthenticator extends javax.mail.Authenticator
{
public PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(senderEmailID, senderPassword);
}
}
public static void main(String[] args)
{     
MailSender mailSender=new
MailSender("typereceivermailid@gmail.com",emailSubject,emailBody);
}
}

Answer 9

试一试。这对我来说很有用。确保在发送电子邮件之前，您需要为您的Gmail帐户中的安全性较低的应用授予访问权限。所以请转到以下链接并尝试使用此java代码 Activate gmail for less secure app

您需要将javax.mail.jar文件和activation.jar文件导入您的项目。

This is the full code for send email in java

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class SendEmail {

    final String senderEmail = "your email address";
    final String senderPassword = "your password";
    final String emailSMTPserver = "smtp.gmail.com";
    final String emailServerPort = "587";
    String receiverEmail = null;
    String emailSubject = null;
    String emailBody = null;

    public SendEmail(String receiverEmail, String Subject, String message) {
        this.receiverEmail = receiverEmail;
        this.emailSubject = Subject;
        this.emailBody = message;

        Properties props = new Properties();
        props.put("mail.smtp.user", senderEmail);
        props.put("mail.smtp.host", emailSMTPserver);
        props.put("mail.smtp.port", emailServerPort);
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.socketFactory.port", emailServerPort);
        props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

        SecurityManager security = System.getSecurityManager();

        try {
            Authenticator auth = new SMTPAuthenticator();
            Session session = Session.getInstance(props, auth);

            Message msg = new MimeMessage(session);
            msg.setText(emailBody);
            msg.setSubject(emailSubject);
            msg.setFrom(new InternetAddress(senderEmail));
            msg.addRecipient(Message.RecipientType.TO,
                    new InternetAddress(receiverEmail));
            Transport.send(msg);
            System.out.println("send successfully");
        } catch (Exception ex) {
            System.err.println("Error occurred while sending.!");
        }

    }

    private class SMTPAuthenticator extends javax.mail.Authenticator {

        public PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(senderEmail, senderPassword);
        }
    }

    public static void main(String[] args) {
        SendEmail send = new SendEmail("receiver email address", "subject", "message");
    }

}

Answer 10

这是工作解决方案兄弟。它是有保障的

1）首先打开您要发送邮件的Gmail帐户，例如“xyz@gmail.com”

2）打开https://support.google.com/accounts/answer/6010255?hl=en

下面的链接

3）点击“转到我的帐户中的”安全性较低的应用“部分。”选项

4）然后打开它

5）就是这样（：

这是我的代码

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class SendEmail {

   final String senderEmailID = "Sender Email id";
final String senderPassword = "Sender Pass word";
final String emailSMTPserver = "smtp.gmail.com";
final String emailServerPort = "465";
String receiverEmailID = null;
static String emailSubject = "Test Mail";
static String emailBody = ":)";
public SendEmail(String receiverEmailID, String emailSubject, String emailBody)
{
this.receiverEmailID=receiverEmailID;
this.emailSubject=emailSubject;
this.emailBody=emailBody;
Properties props = new Properties();
props.put("mail.smtp.user",senderEmailID);
props.put("mail.smtp.host", emailSMTPserver);
props.put("mail.smtp.port", emailServerPort);
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.socketFactory.port", emailServerPort);
props.put("mail.smtp.socketFactory.class","javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");
SecurityManager security = System.getSecurityManager();
try
{
Authenticator auth = new SMTPAuthenticator();
Session session = Session.getInstance(props, auth);
MimeMessage msg = new MimeMessage(session);
msg.setText(emailBody);
msg.setSubject(emailSubject);
msg.setFrom(new InternetAddress(senderEmailID));
msg.addRecipient(Message.RecipientType.TO,
new InternetAddress(receiverEmailID));
Transport.send(msg);
System.out.println("Message send Successfully:)");
}
catch (Exception mex)
{
mex.printStackTrace();
}
}
public class SMTPAuthenticator extends javax.mail.Authenticator
{
public PasswordAuthentication getPasswordAuthentication()
{
return new PasswordAuthentication(senderEmailID, senderPassword);
}
}
    public static void main(String[] args) {
       SendEmail mailSender;
        mailSender = new SendEmail("Receiver Email id","Testing Code 2 example","Testing Code Body yess");
    }

}

Answer 11

我已将我的工作gmail java类放在pastebin上供您查看，特别注意“startSessionWithTLS”方法，您可以调整JavaMail以提供相同的功能。 http://pastebin.com/VE8Mqkqp

Answer 12

除了设置与SMTP服务器的连接之外，您的代码仍然有效。您需要一个正在运行的邮件（SMTP）服务器来为您发送电子邮件。

这是您修改后的代码。我注释掉了不需要的部分，并更改了Session创建，因此需要一个Authenticator。现在只需找出您要使用的SMPT_HOSTNAME，USERNAME和PASSWORD（您的Internet提供商通常会提供它们）。

我总是这样做（使用我知道的远程SMTP服务器），因为在Windows下运行本地邮件服务器并不是那么简单（在Linux下显然很容易）。

import java.util.*;

import javax.mail.*;
import javax.mail.internet.*;

//import javax.activation.*;

public class SendEmail {

    private static String SMPT_HOSTNAME = "";
    private static String USERNAME = "";
    private static String PASSWORD = "";

    public static void main(String[] args) {

        // Recipient's email ID needs to be mentioned.
        String to = "abcd@gmail.com";

        // Sender's email ID needs to be mentioned
        String from = "web@gmail.com";

        // Assuming you are sending email from localhost
        // String host = "localhost";

        // Get system properties
        Properties properties = System.getProperties();

        // Setup mail server
        properties.setProperty("mail.smtp.host", SMPT_HOSTNAME);

        // Get the default Session object.
        // Session session = Session.getDefaultInstance(properties);

        // create a session with an Authenticator
        Session session = Session.getInstance(properties, new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(USERNAME, PASSWORD);
            }
        });

        try {
            // Create a default MimeMessage object.
            MimeMessage message = new MimeMessage(session);

            // Set From: header field of the header.
            message.setFrom(new InternetAddress(from));

            // Set To: header field of the header.
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(
                    to));

            // Set Subject: header field
            message.setSubject("This is the Subject Line!");

            // Now set the actual message
            message.setText("This is actual message");

            // Send message
            Transport.send(message);
            System.out.println("Sent message successfully....");
        } catch (MessagingException mex) {
            mex.printStackTrace();
        }
    }
}

Answer 13

确实有465个工作，你得到的例外可能是由于未打开的SMTP端口25所示。默认情况下，端口号是25.但是你可以使用可用作开源的邮件代理来配置它 - Mercury

为简单起见，只需使用以下配置即可。

// Setup your mail server
props.put("mail.smtp.host", SMTP_HOST); 
props.put("mail.smtp.user",FROM_NAME);
props.put("mail.smtp.ssl.enable", "true");
props.put("mail.smtp.port", "25");
props.put("mail.debug", "true");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.EnableSSL.enable","true");
props.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");  
props.setProperty("mail.smtp.socketFactory.fallback", "false");  
props.setProperty("mail.smtp.port", "465");  
props.setProperty("mail.smtp.socketFactory.port", "465");

更多信息：从头开始查看完整的工作示例 here

Answer 14

我得到了同样的例外。原因是您的计算机没有启动并运行smpt服务器（因为您的主机是localhost）。如果您使用Windows 7，它没有SMTP服务器。所以你必须下载，安装和配置域和创建帐户。我使用hmailserver作为smtp服务器安装和配置在我的本地机器上。 https://www.hmailserver.com/download

Answer 15

您可以在此处找到一个完整且非常简单的java类，用于使用Google（gmail）帐户发送电子邮件，

Send email using java and Google account

它使用以下属性

Properties props = new Properties();
  props.put("mail.smtp.auth", "true");
  props.put("mail.smtp.starttls.enable", "true");
  props.put("mail.smtp.host", "smtp.gmail.com");
  props.put("mail.smtp.port", "587");

使用java发送电子邮件

15 个答案:

2015年12月11日更新

GoogleMail.java

Utils.java