craschworks

Whenever I tried to send someone a text file as an attachment via Thunderbird, the “attachement” would be displayed as inline text when opened in Mail.app. This forum page explains why:

http://forums.mozillazine.org/viewtopic.php?t=121230

Although the fix below doesn't always work, it appears to work for me.

When creating a message, by default Thunderbird treats text attachments as a part of the message body. To force it to encode all attachments as actual separate attachments create a user.js file with the following line:

user_pref(“mail.content_disposition_type”, 1);

(If the user.js file already exists, just add the line above to the bottom of the file.) The file can be found in your Thunderbird profile directory. Here's where I found my profile directory:

/Users/crasch/Library/Thunderbird/Profiles/[randomstring].default

This simply makes tbird always use the

Content-Disposition: attachment;

descriptor in the attachment's header rather than intelligently (or stupidly depending on your point of view) use the default:

Content-Disposition: inline;

for inlineable things like text files.