[Exim] Configuring exim for home use

Godd Day:

I am trying to configure exim 3.03 for a little network I have at home. I
want to send mail to local accounts and to outside (but have the user and
domain changed to my ISP account) Things seem to work fine except on mail
going
to the outside. I setup a filter to change the user name and domain to
my ISP account. However most of the
outgoing mail gets bounced back before the filter is run with the error:
SMTP<< 501 <user@???>... Sender domain must exist

In short does anyone have a config file for this situtation? I tried
C016 it did not seem to work for my version.

Thanks

Mark