Wierd Mail problem

WE set up the mail server aparently OK, However what ever we put in the domainmakes no difference all sent e.amils are sent from the original domain we put in the server domain & host windows. Secondly, the sserver is not recieving mail from anyone... Error in the smtp logs states.... Jun 27 16:49:04 FunServer postfix/smtpd[544]: warning: unknown smtpd restriction: "sbl-xbl.spamhaus.org" Jun 27 16:49:04 FunServer postfix/smtpd[544]: NOQUEUE: reject: RCPT from xxx-97-xxx-xxx.dsl.xxx.co.xxx[xxx.97.xxx.xxx]: 451 Server configuration error; from= to= proto=ESMTP helo= I have blanked out the e.mail address' etc but the error is plain... Neither server is blacklisted... I have switched blacklisting (RBL) off and it make s no difference.... :?