Postfix and MS Exchange

I have an issue: When exchange picks up the email from my Linux Postfix server it kinda mangles it... If the users download the mail from postfix it is just fine, but when Exchange delivers the mail the whole header is shown and all HTML comes through as html code... it cannot be displayed properly.

It has to be a problem with how postfix hands the mail to exchange or how exchange is pulling the mail from postfix...

Anyone seen this before?!?

I've always had problems getting MS Exchange to play nice with linux. Some times exchange wont even recognize linux as a valid smtp server when it's on the same network even though every other email server will.

Funny thing is that I had a Mandrake 8.0 server that would work with exchange just fine (when the rest of the damn system was working)
now I have a Mandrake 7.2 server I had to rebuild that damn 8.0...