Well I have not ever researched this subject of sending Japanese via email really before, I cannot essentially answer your question. I can, however, point you in the direction of your new friend (since you seem like a new user here at the Monastery,)super_search!

I typed in a search for this type of question, and came up with a topic that was asked in the past that might help a little bit on this topic, it was Pyuuta: Programming in Japanese.

If I were you, I would search on the topic of Perl and Unicode programming. This might help you to figure out how to achieve what you are asking.

Hope this helps you somewhat ...

Andy Summers