This is the mail system at host server1.dcomputers.net. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <firstname.lastname@example.org>: host mail1.no-ip.com[220.127.116.11] said: 554 5.7.1 <email@example.com>: Relay access denied (in reply to RCPT TO command) Reporting-MTA: dns; server1.dcomputers.net X-Postfix-Queue-ID: A908527FBFD X-Postfix-Sender: rfc822; firstname.lastname@example.org Arrival-Date: Tue, 13 Jan 2009 10:50:44 -0500 (EST) Final-Recipient: rfc822; email@example.com Original-Recipient: rfc822;firstname.lastname@example.org Action: failed Status: 5.7.1 Remote-MTA: dns; mail1.no-ip.com Diagnostic-Code: smtp; 554 5.7.1 <email@example.com>: Relay access denied 3008 I get alot of messages like that on deferent domain that I am hosting on e-mail user. any segection why? here is how is happen I make an e-mail account on ISPConfig them I sign in my self in Aroundcubemail them I send a test message to my yahoo account them I receive the message them I reply to the message and I get the reply back to aroundcubemail but it come with about 10 messages like the above messages. I do can send and receive messages that is why I am confuse. thank you for your help in advance. PS: I see that show my mail1.no-ip.com that have change to postoffice.no-ip.com but i can't remember where to change that?