Question

我们使用Spring JavaMailSenderImpl 发送邮件。以下是配置

host=XXXX.XXXX.XX
port=25
mail.username=xxxxxxxx
mail.password=xxxxxxx
mail.transport.protocol=smtp
mail.smtp.auth=true
mail.smtp.starttls.enable=true

属性文件： -

Exception in thread "taskExecutor-2" org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: XXXX.XXXX.XX, port: 25;
      nested exception is:
            javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?. Failed messages: javax.mail.MessagingException: Could not connect to SMTP host: XXXX.XXXX.XX, port: 25;
      nested exception is:
            javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?; message exception details (1) are:
    Failed message 1:
    javax.mail.MessagingException: Could not connect to SMTP host: XXXX.XXXX.XX, port: 25;
      nested exception is:
            javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
            at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1934)
            at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:638)
            at javax.mail.Service.connect(Service.java:295)
            at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:389)
            at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
            at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:336)
            at com.XXXX.Mailer$1.run(Mailer.java:52)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
            at java.lang.Thread.run(Thread.java:744)
    Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
            at sun.security.ssl.InputRecord.handleUnknownRecord(InputRecord.java:671)
            at sun.security.ssl.InputRecord.read(InputRecord.java:504)
            at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:927)
            at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1312)
            at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1339)
            at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1323)
            at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:507)
            at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:238)
            at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1900)
            ... 9 more

控制台日志

table1

我们确信这与SSL证书无关，因为在同一服务器中部署了其他Web应用程序，它们使用相同的配置完美地发送电子邮件。这可能是什么问题？

Answer 1

<prop key="mail.smtp.starttls.enable">${mail.smtp.starttls.enable}</prop>
<prop key="mail.smtp.ssl.enable">true</prop>

在TCP连接（端口465）之后，您希望mail.smtp.ssl.enable直接用于隐式SSL;对于使用STARTTLS命令（端口25）的显式SSL，您需要mail.smtp.starttls.enable。但是使用当前属性，您将两者都设置为true。

这意味着它将执行TCP连接到端口25并尝试在那里进行SSL握手。这将失败，因为服务器正在从SMTP对话框发送纯文本问候语而不是预期的SSL握手。因此你得到了

无法识别的SSL消息，明文连接？

要修复它，请确保您使用隐式或显式SSL，但不能同时使用两者，具体取决于端口，即端口25 mail.smtp.ssl.enable应为false。

Answer 2

我尝试通过多种方法解决此问题，但最终发现此问题自己解决了。

在创建代码之前，请确保您能够从Terminal或任何其他邮件客户端发送电子邮件。测试完邮件后，可以正常工作，然后使用以下属性和代码。我已将代码部署在电子邮件服务器中，因此不需要SSL或TLS。我正在使用端口25进行中继。

必需属性-

mail.smtp.host=<myhostname.com>
mail.smtp.port=25
mail.smtp.auth=true
mail.transport.protocol=smtp
smtpd_recipient_restrictions=permit_sasl_authenticated
user=<sender_username/email>
password=<password>
mail.smtp.username=<sender_username/email>
mail.smtp.password=<password>

必需的代码-

public String sendEmail(String email){

         //Compose the message  
          try {  

                FileReader reader=new FileReader("smtp.properties");  
             //Get the session object  
                Properties props = new Properties(); 
                props.load(reader); 

                System.out.println(" Props :: " + props.toString());
                String to = email;
                String host=props.getProperty("mail.smtp.host");
                final String user=props.getProperty("user");
                final String password=props.getProperty("password");

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

                Message message = new MimeMessage(session);
                message.setFrom(new InternetAddress(user));
                message.setRecipients(
                        Message.RecipientType.TO,
                        InternetAddress.parse(to)
                );

                message.setSubject("Testing - SMTP");
                message.setText("Dear User, \n\n Hello !");

                Transport.send(message);

                System.out.println("Done");

               } catch (MessagingException e) {
                    e.printStackTrace();
               } catch (IOException ex) {  
                    ex.printStackTrace();
               }
          return "SUCCESS";
     }

必需的导入-

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.util.Properties;

Answer 3

问题出现在 javax.mail 1.4.0，升级到 1.4.7 解决了我的问题

无法发送邮件 - javax.net.ssl.SSLException：无法识别的SSL消息，明文连接？

3 个答案: