Image embedding in Java mail - CID not working
email, html, image, java
Solution
I found that there wasn't anything wrong with the mail source. It's the way mailclients handle CIDs. Gmail.com requires the CID to be set between < and >. Thunderbird hasn't shown my images yet.. I think it needs to be unique of some sort.. Still haven't figured why and how to fix it. Found it through Embedding images into html email with java mail
Problem
I'm working on an application to send mails to lists etc. It's written in Java using the javax.mail api. The problem here is, I can't embed images using a CID. This is the source of the mail that is sent: ``` Delivered-To: -@gmail.com Received: by 10.43.50.4 with SMTP id vc4csp85536icb; Tue, 17 Apr 2012 05:08:00 -0700 (PDT) Received: by 10.204.141.25 with SMTP id k25mr4406030bku.72.1334664479298; Tue, 17 Apr 2012 05:07:59 -0700 (PDT) Return-Path: <-@gmail.com> Received: from mail-bk0-f43.google.com (mail-bk0-f43.google.com [209.85.214.43]) by mx.google.com with ESMTPS id ad16si7984294bkc.150.2012.04.17.05.07.58 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 17 Apr 2012 05:07:59 -0700 (PDT) Received-SPF: pass (google.com: domain of -@gmail.com designates 209.85.214.43 as permitted sender) client-ip=209.85.214.43; Authentication-Results: mx.google.com; spf=pass (google.com: domain of - designates 209.85.214.43 as permitted sender) smtp.mail=-; dkim=pass header.i=@gmail.com Received: by mail-bk0-f43.google.com with SMTP id j5so5978375bkw.2 for <-@gmail.com>; Tue, 17 Apr 2012 05:07:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:message-id:subject:mime-version:content-type; bh=Xj44O9fBIzirvcquOGxJbYLtbqgBc2Ags7prNUuAtSQ=; b=WWTCdrFgs3RCT/g2qXHR0fLCTc73TmNMA15sff0oIDksB6Nn3IwTYAqTVmoGiNrkW5 08WDpTRADEKAOvjQ5FC9/uBCh1RXWTjxtawfjHc7vfUpqKbXOCj8Ab6GWXQMmX/+WB6T KVYLhk3/+GddIJI1XsAX9zprSYVcP6MMJ5/U+idIDlC7xQGGNuvzvpAnlnlGuWzgKc6j qPoFSAAaio6zICY9uSaI0deBIYTEQ2hIuBDJG8oaRvGVvpjhzJaBK+ab+rPJEboHPg8S 3WSCG/Pp212VOw/YXOLUQV0jmMbuqAbsGdeER+Okbwe11sWi+zvPz+jhplB0NB2wq0Fn mWzA== Received: by 10.204.130.13 with SMTP id q13mr4084640bks.128.1334664478358; Tue, 17 Apr 2012 05:07:58 -0700 (PDT) Return-Path: <-t@gmail.com> Received: from Akoya ([xx]) by mx.google.com with ESMTPS id z14sm37467763bky.15.2012.04.17.05.07.51 (version=SSLv3 cipher=OTHER); Tue, 17 Apr 2012 05:07:54 -0700 (PDT) Date: Tue, 17 Apr 2012 05:07:54 -0700 (PDT) From: BP MM <-@gmail.com> To: xx xx <-@gmail.com> Message-ID: <404745073.01334664469900.JavaMail.xx@Akoya> Subject: TestImage MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2_854532868.1334664469871" ------=_Part_2_854532868.1334664469871 Content-Type: multipart/mixed; boundary="----=_Part_1_1457048287.1334664469871" ------=_Part_1_1457048287.1334664469871 Content-Type: image/png; name=logo.png Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename=logo.png Content-ID: img_cid [base64 data] ------=_Part_1_1457048287.1334664469871-- ------=_Part_2_854532868.1334664469871 Content-Type: multipart/alternative; boundary="----=_Part_0_1033690582.1334664469858" ------=_Part_0_1033690582.1334664469858 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello ------=_Part_0_1033690582.1334664469858 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit <html> <body> <H1>Hello</H1> <img src="cid:img_cid"> </body> </html> ------=_Part_0_1033690582.1334664469858-- ------=_Part_2_854532868.1334664469871-- ``` I've tried different CID's, adding < and > to the CID, setting disposition to inline, validated HTML etc. Can't get this to work, Thunderbird and Gmail view the mail with 'dead' images. I've read that the client looks for the cid in the mail, so I figuered it should fetch the image correctly. Sending the attachment does work, but embedding doesn't. Anyone that has a clue? Is it related to the Multipart structure? The java code for creating the message (i've commented some lines trying to solve it..) ``` /* * The method to create a MimeMessage, this message can be sent with the transport method. */ private Message createMessage(final Mail mail, final Member member, final MailingList list, final MailAccount mailAccount, final Session session) throws MessagingException, UnsupportedEncodingException { // Get attachments @SuppressWarnings("unchecked") List<File> attachments = (List<File>) mail.getProperty(Mail.ATTACHMENTS_KEY); // Create content parts String plainContent = templateEngine.replaceTemplateTags(mail, member, list, mailAccount); String htmlContent = templateEngine.replaceHTMLTemplateTags(mail, member, list, mailAccount); Multipart multiContentPart = new MimeMultipart("alternative"); // Multipart attachmentsBodyPart = new MimeMultipart(); Multipart rootBodyPart = new MimeMultipart(); // Create plain text part if (!plainContent.equals("")) { BodyPart plainMessageBodyPart = new MimeBodyPart(); plainMessageBodyPart.setContent(plainContent, "text/plain"); multiContentPart.addBodyPart(plainMessageBodyPart); } // Create html part if (!htmlContent.equals("")) { BodyPart htmlMessageBodyPart = new MimeBodyPart(); htmlMessageBodyPart.setContent(htmlContent, "text/html"); multiContentPart.addBodyPart(htmlMessageBodyPart); } // Create attachments if (attachments != null && attachments.size() > 0) { for (int i = 0; i < attachments.size(); i++) { BodyPart attachmentBodyPart = new MimeBodyPart(); DataSource source = new FileDataSource(attachments.get(i)); attachmentBodyPart.setDataHandler(new DataHandler(source)); attachmentBodyPart.setFileName(attachments.get(i).getName()); attachmentBodyPart.setHeader("Content-ID", "<img_cid>"); attachmentBodyPart.setDisposition(Part.INLINE); // attachmentsBodyPart.addBodyPart(attachmentBodyPart); rootBodyPart.addBodyPart(attachmentBodyPart); } // Build attachments // BodyPart attachmentsWrapper = new MimeBodyPart(); // attachmentsWrapper.setContent(attachmentsBodyPart); // rootBodyPart.addBodyPart(attachmentsWrapper); } // Build content BodyPart contentWrapper = new MimeBodyPart(); contentWrapper.setContent(multiContentPart); rootBodyPart.addBodyPart(contentWrapper); // Create message Message message = new MimeMessage(session); message.setRecipient(Message.RecipientType.TO, new InternetAddress( member.getEmail(), member.getName())); message.setSubject((String) mail.getProperty(Mail.SUBJECT_KEY)); message.setContent(rootBodyPart); // Add headers message.setFrom(new InternetAddress(mailAccount.getFromAddress(), mailAccount.getFromName())); if (mailAccount.getReplyTo() != "" && mailAccount.getReplyTo() != null) message.setReplyTo(InternetAddress.parse(mailAccount.getReplyTo())); return message; } ``` Don't mind the CID being the same for each attachment, later this will be the file name - I'm only testing with a single attachment for now. Hope this helps..