邮件未发送到Java中的相应用户

<form action="SendMailAttachServlet" method="post" enctype="multipart/form-data">
  <input type="email" name="mailid" value="" required="" size="60" placeholder="Please enter your mail address" />
  <input type="submit" value="Send" />
  <table>

    <tr style="display:none">
      <td>Subject </td>
      <td><input type="text" name="subject" size="50" /></td>
    </tr>
    <tr style="display:none">
      <td>Content </td>
      <td><textarea rows="10" cols="39" name="content"></textarea> </td>
    </tr>
  </table>
</form>

package com.codejava.email;
import java.io.File;
import java.io.IOException;
import java.util.Date;
import java.util.List;
import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
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.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class EmailUtility {
  /**
   * Sends an e-mail message from a SMTP host with a list of attached files.
   *
   */
  public static void sendEmailWithAttachment(String host, String port,
    final String userName, final String password, String toAddress
  )
  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");
    properties.put("mail.user", userName);
    properties.put("mail.password", password);

    // 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());

    // creates message part
    MimeBodyPart messageBodyPart = new MimeBodyPart();
    //  messageBodyPart.setContent(message, "text/html");

    // creates multi-part
    Multipart multipart = new MimeMultipart();
    multipart.addBodyPart(messageBodyPart);


    // sets the multi-part as e-mail's content
    msg.setContent(multipart);

    // sends the e-mail
    Transport.send(msg);
  }

}

package com.codejava.email;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/SendMailAttachServlet")
@MultipartConfig(fileSizeThreshold = 1024 * 1024 * 2, // 2MB
  maxFileSize = 1024 * 1024 * 10, // 10MB
  maxRequestSize = 1024 * 1024 * 50) // 50MB
public class SendMailAttachServlet extends HttpServlet {

  private String host;
  private String port;
  private String user;
  private String pass;

  public void init() {
    // reads SMTP server setting from web.xml file
    ServletContext context = getServletContext();
    host = context.getInitParameter("host");
    port = context.getInitParameter("port");
    user = context.getInitParameter("user");
    pass = context.getInitParameter("pass");
  }


  /**
   * handles form submission
   */
  protected void doPost(HttpServletRequest request,
    HttpServletResponse response) throws ServletException, IOException {

    //  List<File> uploadedFiles = saveUploadedFiles(request);

    String recipient = request.getParameter("recipient");
    //   String subject = request.getParameter("subject");
    //   String content = request.getParameter("content");

    String resultMessage = "";

    try {
      EmailUtility.sendEmailWithAttachment(host, port, user, pass,
        recipient);

      resultMessage = "The e-mail was sent successfully";
    } catch (Exception ex) {
      ex.printStackTrace();
      resultMessage = "There were an error: " + ex.getMessage();
    } finally {
      //deleteUploadFiles(uploadedFiles);
      request.setAttribute("message", resultMessage);
      getServletContext().getRequestDispatcher("/result.jsp").forward(
        request, response);
    }
  }

  /**
   * Saves files uploaded from the client and return a list of these files
   * which will be attached to the e-mail message.
   */



}