When I try to open the attached text file (incidentally, a Nautilus bug-buddy
crash report), I get the following dialog:

***
Cannot open nautilus-bug.txt
The filename "nautilus-bug.txt" indicates that this file is of type "Plain text
document". The contents of the file indicate that the file is of type "Email
message/mailbox". If you open this file, the file might present a security risk
to your system.

Do not open the file unless you created the file yourself, or received the file
from a trusted source. To open the file, rename the file to the correct
extension for "Email message/mailbox", then open the file normally.
Alternatively, use the Open With menu to choose a specific application for the
file. 

   [ Cancel ]
***

There's no security risk for opening text files, so this dialog is silly.