java - 使用 java mail api 发送邮件时出现 MailConnectException

Question

尝试使用 java mail api 发送电子邮件。而且我不断收到 MailConnectException。我尝试了多种方法来解决它但没有成功。

此语句抛出异常

transport.connect("smtp.gmail.com", "someone@gmail.com", "myPassword");

谁能告诉我我做错了什么？

public static void main(String[] args) {
    String host = "smtp.gmail.com";
    String from = "someone@gmail.com";
    Properties props = System.getProperties();
    props.put("mail.smtp.host", host);
    props.put("mail.smtp.user", from);
    props.put("mail.smtp.password", "myPassword");
    props.put("mail.smtp.port", "465"); 
    props.put("mail.smtp.auth", "true");
    try{
        Session session = Session.getDefaultInstance(props, null);
        MimeMessage message = new MimeMessage(session);
        message.setFrom(new InternetAddress(from));
        message.addRecipients(Message.RecipientType.TO, "someone@hotmail.com");
        message.setSubject("sending in a group");
        message.setText("Welcome to JavaMail");
        Transport transport = session.getTransport("smtp");
        transport.connect("smtp.gmail.com", "someone@gmail.com", "myPassword");//CAUSES EXCEPTION
        transport.sendMessage(message, message.getAllRecipients());
    }catch(MessagingException e){
        e.printStackTrace();
    }
}

堆栈跟踪:

com.sun.mail.util.MailConnectException: Couldn't connect to host, port: smtp.gmail.com, 465; timeout -1;
  nested exception is:
    java.net.ConnectException: Connection timed out: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1984)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:656)
    at javax.mail.Service.connect(Service.java:345)
    at javax.mail.Service.connect(Service.java:226)
    at com.karmacrafts.util.CustomEmail.main(CustomEmail.java:127)
Caused by: java.net.ConnectException: Connection timed out: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(Unknown Source)
    at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:301)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:229)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1950)
    ... 4 more

Answer 1

这看起来像是网络问题。尽管它可能由于各种原因而发生，例如:-

“无法连接到主机、端口”可能是由于主机名错误、端口错误、防火墙阻塞(在服务器上、网关上，甚至在您自己的机器上)、网络故障、服务器宕机等

你可以使用 telnet 连接到邮件服务器吗？

另请参阅此常见问题解答以了解您犯下的一些错误 http://www.oracle.com/technetwork/java/javamail/faq/index.html#commonmistakes

阅读有关如何使用 gmail 发送电子邮件的答案 https://stackoverflow.com/a/47452/3107043