auto detect

[farcus]

I often get emails composed in English on a Japanese system.
My girlfriend composes emails in English on the Japanese version of 
Netscape 6.XX and they display just fine when they get to me.
However, the same composed on OE do not display correctly when they get 
to me. I have my computer set to auto detect for Japanese but still have 
to set this manually every time I get such an email composed on 
something other than Netscape.
Is this a known bug?
I'm using Moz 0.9.9 on Win ME.