mail: how to force ALL attachements to display inline?

i'd like to diplay ALL pdf files attachments inline, also the ones that are bigger than 1 page. i know how to force them to appear as icons (defaults write com.apple.mail DisableInlineAttachmentViewing -bool yes), but i want it the other way round…

i actually have an email account that receives faxes as pdf's (1 fax = 1 email with pdf attachement) and it would make my life easier if i could see the contents (attachement) directly even when the attachement is more than 1 page without having to open the attachement first. if the attachement is one page it actually is already displayed inline.

thanks a lot for your hints.

cheers,

cesare