java mail attachments getting corrupted - jakarta-mail

This is my code for attaching the files to the mail:
Multipart mp=new MimeMultipart("mixed");
BodyPart mbody=new MimeBodyPart();
mbody.setHeader("Content-Type", "text/html; charset=us-ascii");
mbody.setHeader("Content-Transfer-Encoding","7bit");
mbody.setContent(content2, "text/html");
mp.addBodyPart(mbody);
for(File file:f){
BodyPart mbody2=new MimeBodyPart();
DataSource ds=new FileDataSource(file.getAbsolutePath());
mbody2.setDataHandler(new DataHandler(ds));
mbody2.setFileName(ds.getName());
mbody2.setHeader("Content-Type", "multipart/mixed");
mbody2.setHeader("Content-Transfer-Encoding", "base64");
mp.addBodyPart(mbody2);
}
m.setContent(mp);
content2 is the html content I am embedding in the E-mail, and I am adding files from an arraylist f.
The problem here is that although the files get attached and I receive the E-mail fine, I am unable to open the attachments because the data is corrupt. This happens for all the files I've tried to attach like jpegs, pdfs, spreadsheets, word docs and txt files.
I read here: https://community.oracle.com/thread/1589120 that this could happen because JavaMail uses encoding that messes up the binary data of the file and adding mbody2.setHeader("Content-Transfer-Encoding", "base64"); should fix the problem but that doesn't work for me.
Any ideas on what could be wrong?
Thanks

Time for some debugging...
First, remove all of the setHeader calls; some of them are wrong and none of them should be necessary.
Next, determine if the problem is on the sending end or the receiving end. Try multiple mail readers to see if they all have problems with the attachments.
Try sending plain text attachments. Are they also corrupted?
Post the protocol trace showing what happens when you send a simple message with a simple attachment that fails, so we can see if the message is being constructed correctly.
What version of JavaMail are you using?
What mail reader are you using to view the attachments?

Related

Discord JDA using a local image in an embed?

Is it possible to use a local image file as a thumbnail/image in an embedded message with Discord JDA?
For one of my commands i'm building an image programmatically and uploading it via the Imgur API before displaying it in an embedded message using the Imgur URL.
I know I can send the file to the channel directly but i'd like it to be contained within an embed that displays other relevant info.
Cheers
You can use attachment://filename.ext as described in the documentation for setImage.
For instance, if you have a file called cat-final-copy-final-LAST.png you can send it like this:
// the name locally is not cat.png but we can still call it cat.png when we send it with addFile
File file = new File("cat-final-copy-final-LAST.png");
EmbedBuilder embed = new EmbedBuilder();
// this URI "attachment://cat.png" references the attachment with the name "cat.png" that you pass in `addFile` below
embed.setImage("attachment://cat.png");
Then send it, with 5.X like this:
// this name does not have to be the same name the file has locally, it can be anything as long as the file extension is correct
channel.sendMessage(embed.build())
.addFiles(FileUpload.fromData(file, "cat.png"))
.queue();
Or with JDA 4.X:
// this name does not have to be the same name the file has locally, it can be anything as long as the file extension is correct
channel.sendMessage(embed.build())
.addFile(file, "cat.png")
.queue();

Unable to retrieve attachments from a signed mail having ContentType as "application/pkcs7-mime; name=smime.p7m"

I am trying to read a digitally signed mail from java code using multipart and mime messaging and fetch the attachments (xml, pdf, txt etc.,) and message details.
My code is working fine for mails having Content-Type as : multipart/signed; protocol="application/x-pkcs7-signature";
But For few mails having Content-Type as : application/pkcs7-mime; smime-type=signed-data; name=smime.p7m it is not fetching the attachments and message details. Can anyone explain what is the difference between both of them and how to resolve it.
I recently came across this issue myself, and although this question is three month old, I leave an answer with my findings, just in case.
Both kinds of messages are instances of S/MIME signed messages as specified in RFC2633 (https://www.rfc-editor.org/rfc/rfc2633).
The multipart/signed; protocol="application/x-pkcs7-signature" indicates a clear-signed message (section 3.4.3.3 of the RFC), meaning you can read the original message content without having S/MIME capabilities in your client code. Hence no problem with these.
The application/pkcs7-mime; smime-type=signed-data; name=smime.p7m indicates an S/MIME signedData email (section 3.4.2) Your client code needs S/MIME capability in order to read the original message (even if you don’t care about the signature).
Easiest way (worked for me) is to use bouncycastle's SMIMESigned class (from the S/MIME API, https://mvnrepository.com/artifact/org.bouncycastle/bcmail-jdk15on), like this:
byte[] content = <the signed data's content as byte[]>;
ByteArrayDataSource dataSource = new ByteArrayDataSource(content,"multipart/signed");
SMIMESigned signedData = new SMIMESigned(new MimeMultipart(dataSource));
MimeBodyPart bodyPart = signedData.getContent();
<you can process the body part as normal from here>

Sending attachments as an email from a form - NOT from local files

I have created a HTML email form which allows a user to enter To, subject, message, content and attachments however I cannot get the attachments to send.
I have researched online and came across many variations of this code:
messageBodyPart = new MimeBodyPart();
String filename = "/home/manisha/file.txt";
DataSource source = new FileDataSource(filename);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(filename);
multipart.addBodyPart(messageBodyPart);
But is there a way of sending attachments input into the form instead of adding the file path to a file in the code?
Thanks
First, the files need to be uploaded from the browser to the server using the html form. Depending on what you're using to manage the uploaded data, you can store the file data in memory or in files on the server. If you store it in memory, you can use a ByteArrayDataSource instead of FileDataSource in your code above.

sending a .rtf file with javaMail

I am trying to get a file with the .rtf extension as an attachment with an email. I cannot seem to get it in my mailbox.
the code I currently use
try
{
Message msg = new MimeMessage(session);
msg.setFrom( ); // this is filled in but hidden for this question
msg.addRecipient();// this is filled in but hidden for this question
msg.setSubject("test email");
msg.setText("body test content");
msg.setSentDate(new Date());
Multipart multipart = new MimeMultipart();
MimeBodyPart messageBodyPart = new MimeBodyPart();
FileDataSource source = new FileDataSource(receiveFile);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.attachFile(backupFile);
messageBodyPart.setFileName("reportFile.rtf");
multipart.addBodyPart(messageBodyPart);
msg.setContent(multipart);
Transport.send(msg);
}
receiveFile is the rtf file in question that needs to be send as an attachement.
Do not bother wtih server settings and such. I have send emails using this code so that works all just fine :). and had success sending .txt or .doc files as well so I know my info is correct. just when I try to send it as reportFile.rtf the mail just does not arrive. and I have tried 2 systems both together (the datahandler + source path and the attachFile path) and both did not really give me what I wanted.
Is a rtf file as attachment possible using javaMail or am I looking in the wrong direction?
After looking at it more closely with my co-worker we figured out that the email I used as sender was interperted as a spam and thus dumped it in the spam folder. now in itself this is not a problem since it was fine for testing. However it seems that if you keep spamming with that address the mail server indeed blocks like a good percentage of the mails i was sending. So this made it hard to debug since it sometimes got through and sometimes did not. the issues has been resolved now.

How can I send a file, for example "exe", with Telnet?

With smtp, i know the commands: "HELO", "MAIL FROM", "RCPT TO", "QUIT", but i don't know how can i attach one file. Anyone can help me ?
telnet smtp.xxxx.xxxx 25
helo xxxx.xxxx
mail from: yyy#xxx.xxx
rcpt to: yy2#xxx.xxx
data
subject: hi
hello
.
quit
This is not something that can be easily done. You probably want to use a library (ex : in python) that will take care of formatting your email according to your needs.
In very brief :
Sending an attachement requires the email to be formatted according to the MIME RFC
A MIME formatted message will use some delimiters to separate the different parts of the message (ex : a plain text part, an HTML part, an attachment part, etc...)
Each MIME part will be prefixed by a header detailing the part content
an attachment part will be identified by a "Content-disposition" header, as detailed in RFC 2183.
The representation of your file will have to be specified using the "Content-Transfer-Encoding" header, described in RFC 2045. A common way to encode files for mail transfer is base64.
If you want to get an idea of how complex it is to generate an email with a valid attachment, you can use your email client to check the source of an email with an attachment (most email clients have this feature). That should eventually convince you to avoid doing this manually :)

Resources