Sorry, could have told you that restarting smtp relay was my first try, but without luck. Still get "220 hostname ESMTP Sendmail 8.14...date" Greeting message is a simple "SMTPD" like your earlier mentioned example.
In a default Scalix installation sendmail is listeining on localhost while omsmtpd tries to catch port 25 on the public IP. compare "netstat -tulpen | grep :25"