Using Content-ID and cid for embedded email images in Thunderbird
I'm generating emails in a PHP application which attach multiple files to an HTML email. Some of the files are Excel spreadsheets, some of the files are company logos which need to be embedded in the HTML so they load by default using Content-ID and cid identifiers to refer to the attached images. As far as I can see, my syntax is correct, but the images don't ever load inline (they are attached successfully, however). From: email@example.com Reply-To: email@example.com MIME-Version: 1.0 Content-type: multipart/mixed;boundary="d0f4ad49cc20d19bf96d4adf9322d567" Message-Id: <20150421165500