如何解决：发送电子邮件到以下服务器失败Socket异常：权限拒绝：连接

Question

我在使用Java编程发送邮件时遇到了这个问题。我从网络团队那里确认，通过Java发送邮件是通过防火墙阻止的。但我可以在windows命令提示符下从telnet获得响应。请查看下面的详细信息。

用于使用Javax mail发送邮件的代码：

public static void main(String[] args) throws MessagingException {
        String host = "mailhost.xxx";
        String to = "[e-mail]";
        String from = "[e-mail]";
        String subject = "test";
        String messageText = "body test";

        Properties props = System.getProperties();
        props.put("mail.host", host);
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.port", "25");

        // If using authentication, otherwise comment out
        props.put("mail.smtp.auth", "true");

        // Gmail requires TLS, your server may not
        props.put("mail.smtp.starttls.enable", "true");

        // Session mailSession = Session.getDefaultInstance(props, null);

        Session mailSession = Session.getInstance(props, new javax.mail.Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication("username", "password");
            }
        });

        Message msg = new MimeMessage(mailSession);
        msg.setFrom(new InternetAddress(from));
        InternetAddress[] address = { new InternetAddress(to) };
        msg.setRecipients(Message.RecipientType.TO, address);
        msg.setSubject(subject);
        msg.setSentDate(new Date());
        msg.setText(messageText);

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

        // connect with authentication
        // transport.connect(host,"myUsername" , "myPassword");

        // connect without authentication
        transport.connect();
        transport.sendMessage(msg, address);

        transport.close();

        System.out.println("Mail was sent to " + to);
        System.out.println(" from " + from);
        System.out.println(" using host " + host + ".");

    }

使用Telnet，我可以在命令提示符下发送邮件：Telnet mailhost。xxx 25我收到的回复如下：

220 mailhost Microsoft ESMTP MAIL Service ready at Tue, 29 Mar 201
6 23:34:36 -0700

在谷歌搜索后，我也尝试在Eclipse中设置JVM参数，如下所示，没有运气仍然得到异常

-Djava.net.preferIPv4Stack=true

例外：

Exception in thread "main" org.apache.commons.mail.EmailException: Sending the email to the following server failed : mailhost.xxx:25
    at org.apache.commons.mail.Email.sendMimeMessage(Email.java:1242)
    at org.apache.commons.mail.Email.send(Email.java:1267)
    at edu.xxx.pageobject.appcenter.util.ReportGenerator.main(ReportGenerator.java:328)
Caused by: javax.mail.MessagingException: Could not connect to SMTP host: mailhost xxx, port: 25;
  nested exception is:
    java.net.SocketException: Permission denied: connect
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1282)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
    at javax.mail.Service.connect(Service.java:297)
    at javax.mail.Service.connect(Service.java:156)
    at javax.mail.Service.connect(Service.java:105)
    at javax.mail.Transport.send0(Transport.java:168)
    at javax.mail.Transport.send(Transport.java:98)
    at org.apache.commons.mail.Email.sendMimeMessage(Email.java:1232)
    ... 2 more
Caused by: java.net.SocketException: Permission denied: connect
    at java.net.TwoStacksPlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at java.net.Socket.connect(Socket.java:528)
    at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:232)
    at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:189)
    at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1250)
    ... 9 more

让我知道解决上述问题的任何可能的解决方案。

Answer 1

为我的上述问题发布了另一个解决方案：在使用Exchange帐户时，我们能够使用EWS（Exchange Web Services）API以编程方式发送邮件。EWS入门指南链接

Answer 2

自：

• 源异常指向权限问题，
• 但您可以使用telnet从命令行进行连接

这不是网络防火墙问题。

您还排除了相关的Java7错误。因此，问题可能来自您的本地Windows防火墙，或者您正在使用的任何防病毒/防火墙。它可能会将权限授予telnet，但不会授予Java。

尝试禁用所有本地防火墙/防病毒软件，并检查java是否可以成功连接。如果是这样，请重新启用防火墙，并创建一个异常规则，以允许连接到Java应用程序的端口25。