Any ideas, apart from "don't do it"?
Three things I'd start with. The first (Don't be angry I'm asking), is to make sure Sendmail is running on the box. If it is not, you will get this message. Then I would make sure DNS is configured correctly and working. Is it resolving other hosts? If you do not have a nameserver configured, Sendmail will send you a connection refused message when it tries to connect to the server. Finally, try looking at the DaemonPortOptions in sendmail.cf. Take out the local host from here (127.0.0.1). Save the file, refresh the daemon and give it another go.
If it's still not working, you may want to try rebuilding your sendmail.cf file again. I know it's painful, but I've seen cases where you spend days looking for the needle when you could get it done much quicker by starting from scratch.
This was first published in May 2003