[exim] Anonymous Remailing Using Exim

I need a way of allowing my employees to communicate with my clients via
email without my employees learning the identity of my clients. I was
thinking of setting up email accounts for each employee and having exim
pipe all incoming and outgoing email to a PERL script that writes them
to text files, encrypts the headers according to some sort of algorithm,
scans the body and attachments for certain strings and then sends it on
its way. My IT guy said that he believes Exim has an anonymity function
add-on that will save me a lot of development time. He didn't know any
more than that. Can anybody clue me in as to whether this exists and
where I might get it? Also, if someone has a similar filtering script
and wants to sell it to me or consult, I'd consider that too. Thanks! -Brad