Hello. I have created a new mailbox in ISPConfig, i can loggin to SquirelMail, and sent messages, but i cannot receive messages. Whan i try to send a new email i get this reply: Code: This is the mail system at host mydomain.com. 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 <email@example.com>: unknown user: "contact" Reporting-MTA: dns; mydomain.com X-Postfix-Queue-ID: B3B29401D5 X-Postfix-Sender: rfc822; firstname.lastname@example.org Arrival-Date: Tue, 10 Nov 2009 16:00:24 +0200 (EET) Final-Recipient: rfc822; email@example.com Original-Recipient: rfc822;firstname.lastname@example.org Action: failed Status: 5.1.1 Diagnostic-Code: X-Postfix; unknown user: "contact" i followed this http://www.howtoforge.com/perfect-server-centos-5.4-x86_64-ispconfig-3 and i didn't have a single error. Can you please help me ? Everything else seems to be working great! Thank you.