Encoding error for mail content with Chinese , Simplicated Chinese or Portuguese

Under DWA interfaces, when the mail content has Chinese , Simplicated Chinese or Portuguese , error encoding appears. No matter what I changed the /Right Click/Encoding … to Utf-8,繁體中文 or simplified chinese, it still doesn’t work. But if i open that mail w/ Notes Client and do the Encoding, every thing works fine. Then reopen that mail again under DWA interface, it works. But the problem s , some users only use DWA interface, they can’t use N.C. to convert the encoding at all. Can someone tell how to config the DWA to accept the Chinese , Simplicated Chinese or Portuguese words??? Many thanks