Dowloading .msg data in IE

[nok]

I have .msg files stored in a database. IIS takes the data, sets the
content-type=application/vnd.ms-outlook and writes it to the client IE.
In IE I get a Save dialog. Saving the file and renming it xxx.msg makes it
open in
Outlook when clicked.
I expected IE to hand the data over to Outlook directly.
Does anyone know how to fix this? BTW I cant find application/vnd.ms-outlook
anywhere in the registry. Shouldnt it be put there by the installation of
Outlook?

Regards Ove