Forward an email(read using JavaMailApi) with Attachments by apache common java api - email

Question

I'm reading messages from an Outlook webmail and getting a list of Messages('javax.mail.Message'). Now I want to forward these Messages to another email address using a java program.
private void sendTestMail(String from, String subject, String sentDate, Object object, Message message)
throws EmailException, Exception {
MultiPartEmail email = new MultiPartEmail();
email.setHostName(forwardHost);
email.addTo(mailRecipients(to));
email.setFrom(emailFrom);
email.setSubject(subject);
email.setMsg("Testing email by sahil.");
EmailAttachment attachment = new EmailAttachment();
attachment.setPath("c:\\sahil\\test.jpg");
attachment.setDisposition(EmailAttachment.ATTACHMENT);
attachment.setDescription("Picture_of_John");
attachment.setName("John.jpg");
email.attach(attachment);
MimeMultipart multiPart = getMimeMultipart(message);
email.addPart(multiPart);
email.send();
}
If I comment below two lines in above code then it works fine.
MimeMultipart multiPart = getMimeMultipart(message);
email.addPart(multiPart);
But with these two line I'm getting exception.
2020-04-20 15:41:44,271 ERROR com.st.ict.ols.service.impl.ReplyToMessageServiceImpl [main] Inner Exception occurred while processing individual message. Error stacktrace is[org.apache.commons.mail.EmailException: Sending the email to the following server failed : smtpapp1.sgp.st.com:25
at org.apache.commons.mail.Email.sendMimeMessage(Email.java:1421)
at org.apache.commons.mail.Email.send(Email.java:1448)
at com.st.ict.ols.service.impl.ReplyToMessageServiceImpl.sendTestMail(ReplyToMessageServiceImpl.java:342)
at com.st.ict.ols.service.impl.ReplyToMessageServiceImpl.processMessage(ReplyToMessageServiceImpl.java:167)
at com.st.ict.ols.service.impl.MessageServiceImpl.processMessage(MessageServiceImpl.java:22)
at com.st.ict.ols.OlsMailSenderApplication.run(OlsMailSenderApplication.java:36)
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:732)
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:716)
at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:703)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:304)
at com.st.ict.ols.OlsMailSenderApplication.main(OlsMailSenderApplication.java:27)
Caused by: javax.mail.MessagingException: IOException while sending message;
nested exception is:
java.io.IOException: Exception writing Multipart
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1308)
at javax.mail.Transport.send0(Transport.java:255)
at javax.mail.Transport.send(Transport.java:124)
at org.apache.commons.mail.Email.sendMimeMessage(Email.java:1411)
... 10 more
Caused by: java.io.IOException: Exception writing Multipart
at com.sun.mail.handlers.multipart_mixed.writeTo(multipart_mixed.java:83)
at javax.activation.ObjectDataContentHandler.writeTo(DataHandler.java:884)
at javax.activation.DataHandler.writeTo(DataHandler.java:317)
at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:1652)
at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:961)
at javax.mail.internet.MimeMultipart.writeTo(MimeMultipart.java:553)
at com.sun.mail.handlers.multipart_mixed.writeTo(multipart_mixed.java:81)
at javax.activation.ObjectDataContentHandler.writeTo(DataHandler.java:884)
at javax.activation.DataHandler.writeTo(DataHandler.java:317)
at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:1652)
at javax.mail.internet.MimeMessage.writeTo(MimeMessage.java:1850)
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1259)
... 13 more
Caused by: javax.mail.MessagingException: Empty multipart: multipart/mixed;
boundary="----=_Part_1_1176580790.1587377502798"
at javax.mail.internet.MimeMultipart.writeTo(MimeMultipart.java:548)
at com.sun.mail.handlers.multipart_mixed.writeTo(multipart_mixed.java:81)
... 24 more
Code I've written to retrieve MimeMultipart from JavaMailApi's Message object to set in apache common's org.apache.commons.mail.MultiPartEmail Object using attach function.
public MimeMultipart getMimeMultipart(Message message) throws Exception {
Object content = message.getContent();
if (content instanceof String)
return null;
if (content instanceof MimeMultipart) {
MimeMultipart multiPartResult = new MimeMultipart();
MimeMultipart multiPart = (MimeMultipart) content;
List<BodyPart> result = new ArrayList<>();
for (int i = 0; i < multiPart.getCount(); i++) {
BodyPart bodyPart = (BodyPart) multiPart.getBodyPart(i);
result.addAll(getMimeMultipart(bodyPart));
}
for(BodyPart part:result) {
multiPart.addBodyPart(part);
}
return multiPartResult;
}
return null;
}
private List<BodyPart> getMimeMultipart(BodyPart part) throws Exception{
List<BodyPart> result = new ArrayList<>();
Object content = part.getContent();
if (content instanceof InputStream || content instanceof String) {
if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition()) || StringUtils.isNotBlank(part.getFileName())) {
result.add(part);
}
return result;
}
if (content instanceof MimeMultipart) {
MimeMultipart multipart = (MimeMultipart) content;
for (int i = 0; i < multipart.getCount(); i++) {
BodyPart bodyPart = (BodyPart) multipart.getBodyPart(i);
result.addAll(getMimeMultipart(bodyPart));
}
}
return result;
}
I was able to forward email excluding attachments but facing issues forwarding with attachments/inline images.
Please help me with this issue.
I'm able to forward the complete message as an attachment, how to forward the message as it is.
MultiPartEmail email = new MultiPartEmail();
MimeMultipart mp = new MimeMultipart();
MimeBodyPart fmbp = new MimeBodyPart();
fmbp.setContent(message, "message/rfc822");
fmbp.setDisposition(Part.INLINE);
mp.addBodyPart(fmbp);
email.setContent(mp);
or if I use code
MimeMultipart mp = (MimeMultipart) message.getContent();
email.setContent(mp, message.getContentType());
I'm getting forwarded email like this
screenshot of forwarded encoded mail

Answer 1

Here the situation is reading mail from one mail server and sending the same message to another email id, within same application.
To achieve this, I used Java Mail API for both reading and sending.
Make sure to update the properties if you're using different host for both steps.
private void sendMailJavax(Message oldMessage) {
try {
// creating a new message using the older message
MimeMessage message = new MimeMessage((MimeMessage)oldMessage);
// updating properties as per sender Mailing API
message.getSession().getProperties().clear();
message.getSession().getProperties().setProperty("mail.smtp.host", forwardHost);
// setting appropriate headers. // make sure you don't append using .add methods.
message.setFrom(new InternetAddress(emailFrom));
message.setRecipient(Message.RecipientType.TO, new InternetAddress(to));
message.setReplyTo(new Address[] { new InternetAddress(replyToEmail)});
Transport.send(message);
System.out.println("Email Sent successfully....");
} catch (MessagingException mex) {
mex.printStackTrace();
}
}