Message Blocked

[Fabio Silva]

Hi all, i had a mail that was blocked on mailscanner, the message has
no executable file, just a attach with the name msg-29120-102.txt but
the message is marked with "Bad Content" and when i open the message
in mailwatch i have this line above in the report option

"Report:	MailScanner: No programs allowed (msg-29120-102.txt)"

In my filename.rules.conf has no deny to .txt just one allow.

Why?? Why this message is blocked?

Regards,
-- 
Fabio S. Silva