UTF-8 chars in user display names do not display right in Email "from" field

(Bug, Investigate , Priority: High, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Email
Summary: Ailis is the classic example: invitations from her come through as "Ail?s".
This probably requires some research into how we need to encode Unicode characters when sending to email. Odds are good that this problem is not limited to the From field.