Relay Problem

I just redid my Microsoft Exchange Server and when I try to send and email to myself using my isp at home this is the error I’m getting. Please help me.

Recipient address: brf@sunshinefeinstein.com
Reason: Remote SMTP server has rejected address
Diagnostic code: smtp;550 5.7.1 Unable to relay for brf@sunshinefeinstein.com
Remote system: dns;mail02.sunshinefeinstein.com (TCP|167.206.5.5|48525|216.5.116.21|25)