Your problem
As far as I can see, it looks like the way you create the message and everything is mostly right! You use the right MIME types and everything.
I am not sure why you use a DataSource and DataHandler, and have a ContentID on the image, but you need to complete your question for me to be able to troubleshoot more. Especially, the following line:
bodyPart.setContent(message, "text/html; charset=ISO-8859-1");
What is in message? Does it contains <img src="cid:image" />?
Did you try to generate the ContentID with String cid = ContentIdGenerator.getContentId(); instead of using image
Source
This blog article taught me how to use the right message type, attach my image and refer to the attachment from the HTML body: How to Send Email with Embedded Images Using Java
Details
Message
You have to create your content using the MimeMultipart class. It is important to use the string "related" as a parameter to the constructor, to tell JavaMail that your parts are "working together".
MimeMultipart content = new MimeMultipart("related");
Content identifier
You need to generate a ContentID, it is a string used to identify the image you attached to your email and refer to it from the email body.
String cid = ContentIdGenerator.getContentId();
Note: This ContentIdGenerator class is hypothetical. You could create one or inline the creation of content IDs. In my case, I use a simple method:
import java.util.UUID;
// ...
String generateContentId(String prefix) {
return String.format("%s-%s", prefix, UUID.randomUUID());
}
HTML body
The HTML code is one part of the MimeMultipart content. Use the MimeBodyPart class for that. Don't forget to specify the encoding and "html" when you set the text of that part!
MimeBodyPart htmlPart = new MimeBodyPart();
htmlPart.setText(""
+ "<html>"
+ " <body>"
+ " <p>Here is my image:</p>"
+ " <img src="cid:" + cid + "" />"
+ " </body>"
+ "</html>"
,"US-ASCII", "html");
content.addBodyPart(htmlPart);
Note that as a source of the image, we use cid: and the generated ContentID.
Image attachment
We can create another MimeBodyPart for the attachment of the image.
MimeBodyPart imagePart = new MimeBodyPart();
imagePart.attachFile("resources/teapot.jpg");
imagePart.setContentID("<" + cid + ">");
imagePart.setDisposition(MimeBodyPart.INLINE);
content.addBodyPart(imagePart);
Note that we use the same ContentID between < and > and set it as the image's ContentID. We also set the disposition to INLINE to signal that this image is meant to be displayed in the email, not as an attachment.
Finish message
That's it! If you create an SMTP message on the right session and use that content, your email will contain an embedded image! For instance:
SMTPMessage m = new SMTPMessage(session);
m.setContent(content);
m.setSubject("Mail with embedded image");
m.setRecipient(RecipientType.TO, new InternetAddress("your@email.com"));
Transport.send(m)
Let me know if that works for you! ;)
