When sending mail from my Hotmail account to my SME5 server I get the following error back in my hotmail account:
Reporting-MTA: dns;hotmail.com
Received-From-MTA: dns;mail.hotmail.com
Arrival-Date: Mon, 12 Nov 2001 13:19:13 -0800
Final-Recipient: rfc822;nightspirit.dyndns.org
Action: failed
Status: 5.0.0
Diagnostic-Code: smtp;501 ... Sender domain must exist
Was is going on here and how can I solve this???