If you are are using microsoft email programs there is provision for changing the encoding and if I am not mistaken you can load one or two different languages eg; chinese and japanese. It only takes two or three clicks. I think you click on the view button and then choose encoding and then scroll down to whatever language you need to decipher.
I'm sure you can download an encoder program from microsoft (if its not already on your cdrom ) which installs itself on the harddisk automatically and when the file is openned the it will automatically produce the kanji in a readable form.
I used to use this method when I wanted to read Japanese on an English ver of windows a while ago.