hello good friends...... i'm new member in this millis. i have problem with my Ms.Exchange server 2003 I have installed the Ms.Exchange server2003, but already received the message like this . What does it mean? rdm_mtc@xxxxxxxxxx on Thu, 15 Dec 2005 10:30:28 +0700 There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <server.dcrepes.com #5.5.0 smtp;501 #5.1.1 bad address rdm_mtc@xxxxxxxxxx> but, i tried to send e-mail via yahoo.com, it was succeed, so whats the matter....? Please Help me....