Adjusting sendmail (I guess)

I'm setting up my Linux box for something new to me. It's on ADSL, and I have my own domain for it. I want all addresses from it to come out as @clicker.org, but right now, it is coming out as @linux.clicker.org (adding the box name) I've used yast to have a domain name of domain.org, and hostname of linux (I have no imagination). I took the sendmail default (but tried the expert configuration too with the same results) "host with permanent internet connection" Any ideas? kathleen