[BUG] attachment without extension .dat Rated 4 out of 5 stars

this is perfect extension for file that have name "winmail.dat". but i have problem if the file doesn't have extension .dat or just winmail. I recieved email with attachment winmail and followed by account name without extension file (example : winmail anderson), so this attachment can't be opened directly by thunderbird.
i can open this attachment with third party program in ubuntu with tnef.
any suggestion ?