Sendmail.cf and forwarding addresses

I have been trying to set up sendmail under Redhat 7.0 for use with
exmh on a Cox cable modem, and have yet to be able to make it
do what I want to do. I have the book on sendmail, but try as I
might it still isn't doing what my interpretation of the book says it
should. Is there a sendmail guru out there who might be able to
give me a few words of advice? I feel pretty comfortable with
this, so I doubt it would take very long.

Thanks for your time and consideration.

       -Lyman