通过Java和Postfix服务器发送SMTP邮件

Question

我想通过使用java发送smtp邮件。我的邮箱编码：

Properties properties = System.getProperties(); 
    properties.put("mail.smtp.auth", "true"); 
    properties.put("mail.smtp.starttls.enable","true"); 
    properties.put("mail.smtp.host", "example.com"); 
    properties.put("mail.smtp.port", "587"); 
    properties.put("mail.smtp.user", "webmaster@example.com"); 
    properties.put("mail.smtp.password", "123456"); 

    Authenticator auth = new Authenticator() { 
     protected PasswordAuthentication getPasswordAuthentication() { 
      return new PasswordAuthentication("webmaster@example.com","123456"); 
     } 
    }; 

    Session mailSession = Session.getInstance(properties, auth); 
    mailSession.setDebug(true); 
    Transport transport = mailSession.getTransport("smtp"); 

example.com是我的postfix服务器主机名。

我已经创建了这个链接我的服务器exacly同样的步骤： http://cnedelcu.blogspot.com.tr/2014/01/how-to-set-up-simple-mail-server-debian-linux.html

和我得到Java错误：

DEBUG: setDebug: JavaMail version 1.4ea 
DEBUG: getProvider() returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun Microsystems, Inc] 
DEBUG SMTP: useEhlo true, useAuth true 
DEBUG SMTP: trying to connect to host "example.com", port 587, isSSL false 
220 example.com ESMTP Postfix (Debian/GNU) 
DEBUG SMTP: connected to host "example.com", port: 587 

EHLO VGate 
250-example.com 
250-PIPELINING 
250-SIZE 10240000 
250-VRFY 
250-ETRN 
250-STARTTLS 
250-ENHANCEDSTATUSCODES 
250-8BITMIME 
250 DSN 
DEBUG SMTP: Found extension "PIPELINING", arg "" 
DEBUG SMTP: Found extension "SIZE", arg "10240000" 
DEBUG SMTP: Found extension "VRFY", arg "" 
DEBUG SMTP: Found extension "ETRN", arg "" 
DEBUG SMTP: Found extension "STARTTLS", arg "" 
DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg "" 
DEBUG SMTP: Found extension "8BITMIME", arg "" 
DEBUG SMTP: Found extension "DSN", arg "" 
STARTTLS 
220 2.0.0 Ready to start TLS 
EHLO VGate 
14:41:49,841 ERROR SystemUsers:253 - Unknown System ErrSor at REST Service 
javax.mail.MessagingException: Can't send command to SMTP host; 
    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.sendCommand(SMTPTransport.java:1420) 
     at com.sun.mail.smtp.SMTPTransport.sendCommand(SMTPTransport.java:1408) 
     at com.sun.mail.smtp.SMTPTransport.ehlo(SMTPTransport.java:847) 
     at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:384) 
     at javax.mail.Service.connect(Service.java:275) 
     at javax.mail.Service.connect(Service.java:156) 

而且，这里是我的邮件日志：

Mar 2 14:43:12 VGate postfix/smtpd[28565]: connect from localhost[127.0.0.1] 
Mar 2 14:43:12 VGate postfix/smtpd[28565]: SSL_accept error from localhost[127.0.0.1]: 0 
Mar 2 14:43:12 VGate postfix/smtpd[28565]: warning: TLS library problem: error:14094416:SSL routines:SSL3_READ_BYTES:sslv3 alert certificate unknown:s3_pkt.c:1294:SSL alert number 46: 
Mar 2 14:43:12 VGate postfix/smtpd[28565]: lost connection after STARTTLS from localhost[127.0.0.1] 
Mar 2 14:43:12 VGate postfix/smtpd[28565]: disconnect from localhost[127.0.0.1] 

我该怎么做才能克服那些错误。

感谢您的帮助。

Answer 1

您的JavaMail实现给您带来错误，因为它表示无法找到受信任的（或受信任的CA签名）证书。为了解决这个问题，就必须在你的Java安装使用“密钥工具”，并添加您的服务器的证书添加到信任证书列表：

keytool -import -alias <some alias> -file <your certificate>.cer -keystore cacerts 

Answer 2

这适用于我。

import java.util.Properties; 

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.MimeMessage; 

public class JavaEmail { 

    Properties emailProperties; 
    Session mailSession; 
    MimeMessage emailMessage; 

    public static void main(String args[]) throws AddressException, 
      MessagingException { 

     JavaEmail javaEmail = new JavaEmail(); 

     javaEmail.setMailServerProperties(); 
     javaEmail.createEmailMessage(); 
     javaEmail.sendEmail(); 
    } 

    public void setMailServerProperties() { 

     String emailPort = "587";//gmail's smtp port 

     emailProperties = System.getProperties(); 
     emailProperties.put("mail.smtp.port", emailPort); 
     emailProperties.put("mail.smtp.auth", "true"); 
     emailProperties.put("mail.smtp.starttls.enable", "true"); 

    } 

    public void createEmailMessage() throws AddressException, 
      MessagingException { 
     String[] toEmails = { "xyz@pqr.com" }; 
     String emailSubject = "Java Email"; 
     String emailBody = "This is an email sent by JavaMail api."; 

     mailSession = Session.getDefaultInstance(emailProperties, null); 
     emailMessage = new MimeMessage(mailSession); 

     for (int i = 0; i < toEmails.length; i++) { 
      emailMessage.addRecipient(Message.RecipientType.TO, new InternetAddress(toEmails[i])); 
     } 

     emailMessage.setSubject(emailSubject); 
     emailMessage.setContent(emailBody, "text/html");//for a html email 
     //emailMessage.setText(emailBody);// for a text email 

    } 

    public void sendEmail() throws AddressException, MessagingException { 

     String emailHost = "smtp.gmail.com"; 
     String fromUser = "your emailid here";//just the id alone without @gmail.com 
     String fromUserEmailPassword = "your email password here"; 

     Transport transport = mailSession.getTransport("smtp"); 

     transport.connect(emailHost, fromUser, fromUserEmailPassword); 
     transport.sendMessage(emailMessage, emailMessage.getAllRecipients()); 
     transport.close(); 
     System.out.println("Email sent successfully."); 
    } 

} 

Answer 3

从JavaMail的常见问题解答：

• When connecting to my mail server over SSL I get an exception like "unable to find valid certification path to requested target".

另外，如果可能的话您使用的是非常旧版本的JavaMail，请upgrade。