Sending a PDF document as a file attachment

Question

Hi,
I have encountered the following problem:
When attaching a pdf document to an email and sending it via Javamail, the resulting PDF document on the other end (i.e. when opened via an email client, such as Outlook) is corrupted and cannot be opened in Acrobar Reader. When doing a side by side comparison with the original file, the emailed document is 1 byte larger than the original (which can possibly cause the "corrupted file error").
Now, this is happening in my company's application and is happening to only one of our customers. This does not happen to 99.9% of them nor can we duplicate it. In addition, it does not happen to all PDF documents, only a few of them.
I have also ensured that our client has the latest version of Javamail and the activation framework jar files.
One thing I have noticed is that the documents are "encoded" as 7bit. This makes sense since the Javadocs explain that if a file is "US-ASCII only" it will be encoded as 7bit, otherwise it will be encoded as base64. Many of our PDF documents are text only.
My side question is, is there a way to force it to encode it as base64 for all pdf documents and would this help?
My main question is: Does anyone know what is happening and what I can do about it?
Anyway, here is the code fragment that does the attachment:
                      for (int i = 0; i < attachments.length; i++)
                         messageBodyPart = new MimeBodyPart();
                         FileDataSource fileDataSource = new FileDataSource(attachments);
                         messageBodyPart.setDataHandler(new DataHandler(fileDataSource));
                         String fileName = attachments[i].getName();
                         messageBodyPart.setFileName(fileName);
                         multipart.addBodyPart(messageBodyPart);
Where attachments is a File array.

Answer 1

Only one of your customers. And they can only handle base-64 encoding and not 7-bit encoding of mail messages.
We had the same thing. We send thousands of files every week using JavaMail, most of them PDFs and other files that are all text. Just one of our customers had some cruddy mail handler they had written themselves, or something like that, and it only liked base-64 encoded messages. This was fine for them because MS Outlook automatically does that for attachments regardless, and everybody was using Outlook to send them files. Except us. So we had to set up a hokey scheme where we would send their messages to a local MS Exchange address and have them auto-forwarded to the customer's address. (I couldn't find any way to control base-64 versus 7-bit encoding.)
But that customer wasn't using Outlook to read the messages, so maybe that isn't the problem. We also had a supplier (fortunately an ex-supplier now) who we used to send zip files to (from Outlook even) and their mail server would insert extra line breaks into the attachment, thus making the zip file corrupted. Maybe something like that is happening.
We had another customer who used Lotus Notes as their mail server, and it couldn't deal with our plain ordinary PDFs either. But I think Notes must have had some bug fixes because I haven't heard about that problem lately.
Good luck.