http://www.perlmonks.org?node_id=1060441


in reply to Re^2: decoding a UTF-16B string found in an email subject
in thread decoding a UTF-16B string found in an email subject

If you just subsitute 'UTF-16' with 'UTF-8', then the entire line is correctly decoded with decode('MIME-Header', $str). The encoded part appears to be incorrectly encoded. Probably typical of spammers...