Handle embedded (INLINE) resources as attachments if the cid identifier doesn't occur in the HTML body

[jkxyx205]

Hi, Benny Bottema

I have a problem, the details are as follows。

1. Scene description

Here is my hello.eml file which include a attachment and a embedded image exported by client application Foxmail. Open with outlook screenshot below:

2. Parse eml but can't get any information

Email oldEmail = EmailConverter.emlToEmail("/Users/rick/jkxyx205/tmp/hello.eml");

[bbottema]

Can you perform the same check for EmailConverter.emlToMimeMessage() please?

[jkxyx205]

I can't parse any thing either.

return new MimeMessage(session, new ByteArrayInputStream(eml.getBytes(UTF_8)));

Maybe java.mail does not have the ability to parse this file but outlook can.

[bbottema]

Hmm, maybe this EML requires a specific javax.mail version? I'll give it a try as well, but I'm affraid this is a limitation of the underlying Java Mail framework.

[bbottema]

I'm getting a completely empty result without errors.

For what it's worth, the EML is not validating the following validation tools:

• tools.gbif.org/dwca-validator/eml
• knb.ecoinformatics.org/emlparser
• tools.ietf.org/tools/msglint

But mimevalidator.net thinks it's fine.

[bbottema]

Sorry, I got confused. It's working fine for me. Here's my result:

InputStream resourceAsStream = EmailHelper.class.getClassLoader().getResourceAsStream("test-messages/hello.eml");
Email e =  EmailConverter.emlToEmail(resourceAsStream);

Perhaps it wasn't clear from the API, but the method you used expetcs EML data, not a filepath string.

Email oldEmail = EmailConverter.emlToEmail("/Users/rick/jkxyx205/tmp/hello.eml"); // <-- this should be file content

[jkxyx205]

Yes, you are right, what a ridiculous mistake I did.

But I found another problem, lost a embeded image as I metioned #173, but 2 attachments

[bbottema]

If an embedded attachment isn't actually embedded it is treated as an attachment. Is it being used in the body?

[jkxyx205]

Outlook treat the mail as a attachment and a embedded image.

Ok,I will continue to track it later. Thank you for your help, simple-java-mail excellent framework!!!

[jkxyx205]

Hmm, finally I got the root cause.

When export EML by client foxmail which does't specify header Content-Disposition: inline; filename=image.png when it is a embedded image. If the disposition is not provided, the part be treated as attachment by simple-java-mail.

See org.simplejavamail.converter.internal.mimemessage.MimeMessageParser.java

private static void parseMimePartTree(@Nonnull final MimePart currentPart, @Nonnull final ParsedMimeMessageComponents parsedComponents) {
		for (final Header header : retrieveAllHeaders(currentPart)) {
			parseHeader(header, parsedComponents);
		}
		
		final String disposition = parseDisposition(currentPart);
		
		if (isMimeType(currentPart, "text/plain") && parsedComponents.plainContent == null && !Part.ATTACHMENT.equalsIgnoreCase(disposition)) {
			parsedComponents.plainContent = parseContent(currentPart);
		} else if (isMimeType(currentPart, "text/html") && parsedComponents.htmlContent == null && !Part.ATTACHMENT.equalsIgnoreCase(disposition)) {
			parsedComponents.htmlContent = parseContent(currentPart);
		} else if (isMimeType(currentPart, "multipart/*")) {
			final Multipart mp = parseContent(currentPart);
			for (int i = 0, count = countBodyParts(mp); i < count; i++) {
				parseMimePartTree(getBodyPartAtIndex(mp, i), parsedComponents);
			}
		} else {
			final DataSource ds = createDataSource(currentPart);
			// If the diposition is not provided, the part should be treated as attachment
			if (disposition == null || Part.ATTACHMENT.equalsIgnoreCase(disposition)) {
				parsedComponents.attachmentList.put(parseResourceName(parseContentID(currentPart), parseFileName(currentPart)), ds);
			} else if (Part.INLINE.equalsIgnoreCase(disposition)) {
				if (parseContentID(currentPart) != null) {
					parsedComponents.cidMap.put(parseContentID(currentPart), ds);
				} else {
					// contentID missing -> treat as standard attachment
					parsedComponents.attachmentList.put(parseResourceName(null, parseFileName(currentPart)), ds);
				}
			} else {
				throw new IllegalStateException("invalid attachment type");
			}
		}
	}

If I add Content-Disposition: inline; filename=image.png manually, it works fine. ˆ-ˆ

So my question is coming, why can't I treated as embedded image if disposition is not provided，behaves normally like Outlook.

[jkxyx205]

BTW, Outlook, Mac Mail, Foxmail can parse hello.eml correctly, one attachment + one embedded image.