In the comparatively rare cases, such as yours, where the unwanted messages have a consistent distinguishing factor I'd look at setting up a filter to deal with them. However, it's quite possible that there is no specific mention of the language being used. The junk training system looks at the frequency of words being used in email messages. It doesn't care what language they are in, as it doesn't try to understand the words, and the tiny part of email message headers that declare the encoding, even if it specifically mentioned a language (and that's unlikely with the spreading use of unicode) almost certainly isn't included in the Junk Controls' analysis of your messages. Spammers often load their messages with large swathes of random text, usually hidden, which "dilute" the spammy part of their message. The word counter gets busy counting all the normal words, and so the relative contribution of spammy words is small in proportion to the entire message's word count. Keep on training; it may eventually collect enough words in the foreign language to be able to develop an association with their spamminess.