無法使用Javax.mail發送郵件

Question

我正在嘗試使用javax.mail API在帶有Java 1.8的Windows 8.1上發送電子郵件，但我一直收到錯誤消息。

這是我寫的方法：

public void sendAlertMail(String from, String to, String header, String msgBody){
        Properties props = new Properties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.host", smptHost);
        props.put("mail.smtp.port", smptPort);
        props.put("mail.smtp.starttls","true");
        Session mailSession;
        if (authenticate) {
            props.put("mail.smtp.auth", "true");

            Authenticator auth = new SMTPAuthenticator();
            mailSession = Session.getInstance(props, auth);
        }
        else{
            mailSession = Session.getInstance(props);
        }
        // uncomment for debugging infos to stdout
        // mailSession.setDebug(true);
        Transport transport = null;
        try {
            transport = mailSession.getTransport();
        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        }

        MimeMessage message = new MimeMessage(mailSession);
        try {
            message.addHeaderLine(header);
            message.setContent(msgBody, "text/plain");
            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO,
                    new InternetAddress(to));
        } catch (MessagingException e) {
        }
        try {
            transport.connect();
            transport.sendMessage(message,
                    message.getRecipients(Message.RecipientType.TO));
            transport.close();
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }

我收到的錯誤是：

com.sun.mail.util.MailConnectException: Couldn't connect to host, port: smtp.gmail.com, 587; timeout -1;
  nested exception is:
    java.net.SocketException: Permission denied: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2100)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:699)
    at javax.mail.Service.connect(Service.java:388)
    at javax.mail.Service.connect(Service.java:246)
    at javax.mail.Service.connect(Service.java:195)
    at tapperSolution.mail.MailSender.sendAlertMail(MailSender.java:64)
    at tapperSolution.mail.MailSender.sendAlertMail(MailSender.java:74)
    at tapperSolution.mail.MailSender.main(MailSender.java:88)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
Caused by: java.net.SocketException: Permission denied: connect\at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at java.net.Socket.connect(Socket.java:538)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:331)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:238)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2066)
... 12 more

我關閉了防火牆和防病毒軟件，並嘗試使用以下命令在代碼中設置VM選項：

System.setProperty("java.net.preferIPv4Stack", "true");

還嘗試使用以下命令在run命令中進行設置：

-Djava.net.preferIPv4stack = true

我可以使用Python發送郵件，但我想使用Java發送郵件。

試圖使用Wireshark捕獲流量，但是服務器之間甚至沒有TCP握手。

還有其他想法嗎？

謝謝

Answer 1

看來您的SMTP服務器可能由於身份驗證問題而拒絕了您的連接。 要對此進行測試，請嘗試從同一台計算機進行手動SMTP會話 ，然后查看結果。