Yes it does. Email Marketer supports more than 30 country languages / charsets.
All you need to do is to pick the corresponding charset in Publish View. And if
you are sending HTML messages, click Format | Page Property and select the Language.
In this HTML source example we're using the JAPANESE Shift_JIS charset:
<meta http-equiv="Content-Type" content="text/html; charset=Shift_JIS">