通过Java使用gmail发送电子邮件

我正试图使用以下代码通过java发送电子邮件：

package send_email;
import java.util.Properties;  
import javax.mail.*;  
import javax.mail.internet.*;  
/**
 *
 * @author A
 */
public class Send_email {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        String host="smtp.gmail.com";  
  final String user="***@gmail.com";//change accordingly  
  final String password="****";//change accordingly  

  String to="*******@gmail.com";//change accordingly  

   //Get the session object  
   Properties props = new Properties();  
   props.put("mail.smtp.host",host);  
   props.put("mail.smtp.auth", "true");  

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

   //Compose the message  
    try {  
     MimeMessage message = new MimeMessage(session);  
     message.setFrom(new InternetAddress(user));  
     message.addRecipient(Message.RecipientType.TO,new InternetAddress(to));  
     message.setSubject("javatpoint");  
     message.setText("This is simple program of sending email using JavaMail API");  

    //send the message  
     Transport.send(message);  

     System.out.println("message sent successfully...");  

     } catch (MessagingException e) {e.printStackTrace();} 
    }

}

但我得到了以下错误：

javax.mail.MessagingException: Could not connect to SMTP host: smtp.gmail.com, port: 25, response: 554
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1694)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)
    at javax.mail.Service.connect(Service.java:313)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at send_email.Send_email.main(Send_email.java:48)
BUILD SUCCESSFUL (total time: 0 seconds)

javax.mail.MessagingException: Could not convert socket to TLS;
  nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1652)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:534)
    at javax.mail.Service.connect(Service.java:313)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at send_email.Send_email.main(Send_email.java:52)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1946)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:316)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:310)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1640)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1395)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1379)
    at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:503)
    at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:443)
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1647)
    ... 7 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:302)
    at sun.security.validator.Validator.validate(Validator.java:262)
    at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:330)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:237)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:132)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1622)
    ... 17 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
    ... 23 more

我允许端口25通过防火墙，然后我使用telnet“telnet smtp.gmail.com 25”对其进行了测试，但我得到了这个错误 554 OutgoingFilter“由于发送垃圾邮件或病毒，您被临时推迟 有关更多信息，请联系16333“

那么我该如何修复这个错误呢

编辑：我现在通过Telnet收到此错误“421无法连接到SMTP服务器108.177.15.109（108.177.15.109:25），请连接 ror 10060

与主机的连接丢失。 " 编辑_2：我发现gmail SMTP的端口是587，我已经相应地将会话对象更改为

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

这个代码是在那里提供的。但是，我得到以下错误：

javax.mail.MessagingException: Could not connect to SMTP host: smtp.gmail.com, port: 25, response: 554
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1694)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:525)
    at javax.mail.Service.connect(Service.java:313)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at send_email.Send_email.main(Send_email.java:48)
BUILD SUCCESSFUL (total time: 0 seconds)

javax.mail.MessagingException: Could not convert socket to TLS;
  nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1652)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:534)
    at javax.mail.Service.connect(Service.java:313)
    at javax.mail.Service.connect(Service.java:172)
    at javax.mail.Service.connect(Service.java:121)
    at javax.mail.Transport.send0(Transport.java:190)
    at javax.mail.Transport.send(Transport.java:120)
    at send_email.Send_email.main(Send_email.java:52)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1946)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:316)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:310)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1640)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1395)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1379)
    at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:503)
    at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:443)
    at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1647)
    ... 7 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:302)
    at sun.security.validator.Validator.validate(Validator.java:262)
    at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:330)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:237)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:132)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1622)
    ... 17 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
    ... 23 more

然而，当通过这个新端口连接时，telenet给了我以下信息：220 smtp.gmail.com ESMTP a24sm5897091wmb.29-gsmtp 我想这意味着我是通过telnet连接的。

试试这些设置

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

试试这些设置

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

---

您可以使用以下技术之一获取SMTP服务器：

安装并使用任何SMTP服务器，如Postcast服务器、Apache 詹姆斯服务器、电子邮件服务器等

使用主机提供程序提供的SMTP服务器，例如my SMTP 服务器是mail.xxx.com

使用其他公司提供的SMTP服务器，如Gmail等

要使用JavaMail API发送电子邮件，需要加载两个jar文件： -mail.jar -激活.jar 下面是一个例子

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

    public class TestSendEmail {

       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 = "test@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(Subject Line!");

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

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

---

您可以使用以下技术之一获取SMTP服务器：

安装并使用任何SMTP服务器，如Postcast服务器、Apache 詹姆斯服务器、电子邮件服务器等

使用主机提供程序提供的SMTP服务器，例如my SMTP 服务器是mail.xxx.com

使用其他公司提供的SMTP服务器，如Gmail等

要使用JavaMail API发送电子邮件，需要加载两个jar文件： -mail.jar -激活.jar 下面是一个例子

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

    public class TestSendEmail {

       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 = "test@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(Subject Line!");

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

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

---

这与你的gmail帐户和谷歌政策有关。也许我会打16333。你在过去的24小时里运行了多少次这个程序？如果你试图在短时间内发送邮件太多次，邮件中继会将你视为垃圾邮件来源，这与你的gmail帐户和谷歌政策有关。也许我会打16333。你在过去的24小时里运行了多少次这个程序？如果您试图在短时间内发送邮件太多次，邮件中继会将您视为垃圾邮件源，这是有道理的；我发现javax.mail.MessaginException错误：无法将套接字转换为TLS；