I'm composing emails in Thunderbird. When I attach png images by dragging to the header region, they are attached as
Content-Type: image/png; name="foo.png" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="foo.png"
When I attach them inline by dragging into the body, they are attached as
Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: base64 Content-ID: <email@example.com>
The latter displays fine for the recipient if they are using Thunderbird, or via the gmail web interface. However, I've had complaints from OSX Mail.app users that they can only see a text file
<Mail Attachment.txt> full of nonsense. They have to save the file and rename it to
Also kmail is confused by this attachment, although it seems to get some information from the attachment:
Should the attachments not be sent as
text/plain? (However, it's interesting that Gmail understands it.) If so, then how can I make Thunderbird send inline attachments as the proper mime type?