When I send a PDF attachment, the PDF content is displayed as binary data converted to text after the message body.
This occurs in mail in my "Sent mail" and in the recipient's inbox.
Thunderbird 24.6.0 on Mac OS 10.7
Do you have ways to identify the cause of this problem?
Like the question asker already found themselves, according to an old bug report, this is caused by:
When [sending] an email with a PDF document attached, the Content-Type is set to text/plain, while they should be application/pdf
...which itself is due to:
[...] you may have picked up a wrong content-type definition when opening an attachment with such a specification, then making it the default action by checking the box which is in the respective dialog. This associates the extension of that file name with the given content type and will be used for outgoing e-mail from that point on.
...and solved by:
Find the
mimeTypes.rdffile in your profile folder (not the default copy in your installation folders), then rename it while Thunderbird is down. Restarting will create a new file from the default template, and the issue should be gone. You can use the new file if you don't have a significant number of definitions, or replace it with the old one and use the MIME Edit extension to remove the faulty entry.
