User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0 Build ID: 20111104165243 Steps to reproduce: I received two e-mails with embedded images (using PNG, GIF, and JPG formats) that displayed as blank boxes. The "View Message Body As" option is set to "Original HTML" and the "Display Attachments Inline" option is checked. Changing these settings did not affect the problem. Actual results: I found a work-around by installing the third party add-on "Show All Body Parts". Changing the option "View Message Body As" from "Original HTML" to "All Body Parts" made the embedded graphics visible as file attachments at the bottom of the page and allowed me to open and display them using Windows Photo Viewer. Expected results: Thunderbird should have displayed these images directly without the Add-on or the cumbersome settings changes. The e-mail I am attaching has the embedded PNG image. I would like to attach both files but your template only allows one file to be attached. I suggest you modify this to allow additional file attachments as needed.

Second e-mail attached from this template.

(In reply to FH from comment #2) Here is the story of the extension: https://addons.mozilla.org/en-US/thunderbird/addon/show-all-body-parts/developers

Content-Type: multipart/related; boundary="----=_NextPart_000_0012_01CCBC0E.ECBD3A50"

Well, it says Content-Type: image/unknown; and Content-Type: unknown/unknown;