Split from this thread.
I started having this issue since upgrading to Sierra too (10.12.4). I have applied all Office updates (now on 14.7.4) since encountering it, and the problem persists.
The problem happens with both plain text and HTML format messages. And it happens whether I am pasting images directly into the email body, or attaching a JPG or PNG file.
The native Mac Mail client sends images just fine, so I don't think it's a pure OS issue, but clearly there is an issue between Office 2011 and Mac OS Sierra.
Digging a little further, what I have found is that JPG/PNG attachments are now being encoded with MIME type application/applefile instead of image/xxx. From what I can tell, the attachment is actually there, just not encoded in a format most email clients seem willing to handle as an image. What this means is that if I forward an email (which doesn't 'show' the image) from one of those clients, the image is then accessible/visible.
Below is an excerpt of the encoding from an email that exhibits the problem:
--B_3579799937_118424173Content-type: application/applefile; name="app store icon v2 1024x1024.png"
Content-transfer-encoding: base64
Content-disposition: attachment;
filename="app store icon v2 1024x1024.png"
------------------------------------------------------------------------------
Contrast that to how images were encoded prior to the Sierra upgrade where images appear just fine:
--B_3544378288_16945287Content-Type: image/png; name="default.png"
Content-Disposition: attachment; filename="default.png"
Content-Transfer-Encoding: base64
I know the support cycle on 2011 is coming to an end, but is there any chance we can get a fix or workaround on this? It is getting a bit tedious to either convert the image to a PDF or to send and forward the email in order to get the image visible to recipients.
Thank you,
Yannis.
