这是应用程序的代码。我一直在尝试使用Eclipse IDE运行它。我也添加了所有必需的Java邮件jar文件，即dsn.jar、imap.jar、mailapi.jar、pop3.jar、smtp.jar和mail.jar。但是会出现以下错误：无法连接到SMTP主机：smtp.gmail.com，端口：587。
没有防火墙阻止访问，因为在ping smtp.gmail.com时收到了回复。我甚至尝试过以下方法：
- 首先在设备上的浏览器中登录Gmail帐户并设置/使用客户端
- 在此处启用“较不安全”的应用程序访问权限：https://www.google.com/settings/security/lesssecureapps
- 然后转到此处：https://accounts.google.com/b/0/DisplayUnlockCaptcha 并单击“继续”。
- 然后立即返回您的客户端并重试。
javax.mail.MessagingException: Could not connect to SMTP host: smtp.gmail.com, port: 587; nested exception is: java.net.ConnectException: Connection timed out: connect at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1972) at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:642) at javax.mail.Service.connect(Service.java:317) at javax.mail.Service.connect(Service.java:176) at javax.mail.Service.connect(Service.java:125) at javax.mail.Transport.send0(Transport.java:194) at javax.mail.Transport.send(Transport.java:124) at PlainTextEmailSender.sendPlainTextEmail(PlainTextEmailSender.java:50) at PlainTextEmailSender.main(PlainTextEmailSender.java:73) Caused by: java.net.ConnectException: Connection timed out: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) at java.net.AbstractPlainSocketImpl.connect(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:319) at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:233) at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1938)
package net.codejava.mail;
import java.util.Date;
import java.util.Properties;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
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 PlainTextEmailSender {
public void sendPlainTextEmail(String host, String port,
final String userName, final String password, String toAddress,
String subject, String message) throws AddressException,
MessagingException {
// sets SMTP server properties
Properties properties = new Properties();
properties.put("mail.smtp.host", host);
properties.put("mail.smtp.port", port);
properties.put("mail.smtp.auth", "true");
properties.put("mail.smtp.starttls.enable", "true");
// creates a new session with an authenticator
Authenticator auth = new Authenticator() {
public PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(userName, password);
}
};
Session session = Session.getInstance(properties, auth);
// creates a new e-mail message
Message msg = new MimeMessage(session);
msg.setFrom(new InternetAddress(userName));
InternetAddress[] toAddresses = { new InternetAddress(toAddress) };
msg.setRecipients(Message.RecipientType.TO, toAddresses);
msg.setSubject(subject);
msg.setSentDate(new Date());
// set plain text message
msg.setText(message);
// sends the e-mail
Transport.send(msg);
}
/**
* Test the send e-mail method
*
*/
public static void main(String[] args) {
// SMTP server information
String host = "smtp.gmail.com";
String port = "587";
String mailFrom = "user_name";
String password = "password";
// outgoing message information
String mailTo = "email_address";
String subject = "Hello my friend";
String message = "Hi guy, Hope you are doing well. Duke.";
PlainTextEmailSender mailer = new PlainTextEmailSender();
try {
mailer.sendPlainTextEmail(host, port, mailFrom, password, mailTo,
subject, message);
System.out.println("Email sent.");
} catch (Exception ex) {
System.out.println("Failed to sent email.");
ex.printStackTrace();
}
}
}