What do I have to tell sendmail to let spamd process the incoming mail ?
Two methods:
You can install a "milter" to invoke spamassassin from sendmail. Several are available, although I don't believe any ship in Fedora. I use MIMEDefang (http://mimedefang.org/).
You can invoke spamc (the client for spamd) from /etc/procmailrc. For example, put this in that file:
# -- top of example -- # this is needed to let spamc tell spamd what user's config to use # and to insure Sanitizer is run as regular user to limit possible damage DROPPRIVS=YES
# first run spamassassin if message is small enough :0fw * < 200000 | /usr/bin/spamc # -- end of example --
