In Outlook (2003, 2007, 2010) you can block mails with "unfamiliar characters", based on their Encodings.
From the Outlook 2007 Junk E-Mail Filter section ...
Block messages in unfamiliar alphabets
You can block all e-mail addresses in
language encodings (also known as
character sets, or alphabets) that you
specify. Today, most junk e-mail is
sent in the US-ASCII encoding. The
remainder is sent in various other
international encodings. The Blocked
Encodings List lets you filter out
unwanted e-mail that is displayed in
languages that you don't understand.
On the Tools menu, click Options to open the Options dialog box.
On the Preferences tab, under E-mail, click Junk E-mail to open the Junk E-mail Options dialog box.
Click the International tab, and then click Blocked Encodings List.
In the list, click the language encoding that you want to block, or click Select All.
Click OK twice.