I've an idea restart from zero the post, I try to explain better.
Start customizing from IPM.Note form. When I test custom form in outlook
designer (in italian version is "esegui modulo" in english I think is
something like "execute form"), the icon is the standard, close when unread
and open after reading it.
I publish the custom form, select it from personal module, send mail the
icon is closed on unread and closed after read the message.
PS: this weekend I search my school english book, and re-read it ;-)