title: .zip file gets converted to .bin file while sending the email in java
body: <p>I am trying to send mail using below snippet with the <code>zip file</code> as attachment,I am able to send the email but the attachment which is zip file gets converted to some <code>.bin</code> file.
  Do I need to set some properties?
  Why zip file gets converted to .bin file?  </p>
  
  <pre><code>Properties props = new Properties();
              props.setProperty("mail.transport.protocol", "smtp");
              props.setProperty("mail.host", "smtp.gmail.com");
  
              Session mailSession = Session.getDefaultInstance(props, null);
              mailSession.setDebug(true);
              Transport transport = mailSession.getTransport();
  
              MimeMessage message = new MimeMessage(mailSession);
              message.setSubject("HTML  mail with images");
              message.setFrom(new InternetAddress("b@gmail.com"));
              message.addRecipient(Message.RecipientType.TO,
                   new InternetAddress("a@gmail.com"));
              MimeMultipart multipart = new MimeMultipart("related");
  
              // first part  (the html)
              BodyPart messageBodyPart = new MimeBodyPart();
              String htmlText = "PFA Query Output.";
              messageBodyPart.setContent(htmlText, "text/html");
  
              // add it
              multipart.addBodyPart(messageBodyPart);
  
              // second part (the image)
              messageBodyPart = new MimeBodyPart();
              DataSource fds = new FileDataSource(zipFilePath);
              messageBodyPart.setDataHandler(new DataHandler(fds));
              messageBodyPart.setHeader("Content-ID","&lt;image&gt;");
  
              // add it
              multipart.addBodyPart(messageBodyPart);
  
              // put everything together
              message.setContent(multipart);
  
              transport.connect();
              transport.sendMessage(message,
                  message.getRecipients(Message.RecipientType.TO));
              transport.close();
  </code></pre>