Have a look at Mimedefang
This is what I use & install for organisation wide spam & virus filtering.
Another one I have come across is
but I have never used it.
And yes use the Milter API this is what its designed for.
1) is sendmail with FC1.0 compiled with the Milter API enabled ?
I'm not sure but I expect that it is.
2) if not, is there anything I need to consider in downloading the
and installing from
that - other than following the normal instructions ?
If you mean the Sendmail source I wouldn't. I'd download the fedora sendmail
src rpm and rebuild it with what ever extra options you require.