I'm having a problem with my mail server. My setup is an Ubuntu 7.10 and completed the server with the help of The Perfect Server tutorial. For some reason i cannot recieve e-mails, and e-mails being sent is being bounced back. I've read through every forum and searched for answers but apparently my issue seems different from the others. Here is my E-mail that got bounced back. Code: This is the mail system at host server00.gnwebhosting.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 <GN1_tek@server00.gnwebhosting.com> (expanded from <firstname.lastname@example.org>): unknown user: "gn1_tek" Final-Recipient: rfc822; GN1_tek@server00.gnwebhosting.com Original-Recipient: rfc822;email@example.com Action: failed Status: 5.1.1 Diagnostic-Code: X-Postfix; unknown user: "gn1_tek" Received: from imo-d22.mx.aol.com (imo-d22.mx.aol.com [18.104.22.168]) by server00.gnwebhosting.com (Postfix) with ESMTP id 3F0E28BC64B for <firstname.lastname@example.org>; Wed, 26 Mar 2008 16:37:26 -0400 (EDT) Received: from email@example.com by imo-d22.mx.aol.com (mail_out_v38_r9.3.) id r.d35.219ec3c7 (30739) for <firstname.lastname@example.org>; Wed, 26 Mar 2008 16:37:17 -0400 (EDT) From: email@example.com Message-ID: <firstname.lastname@example.org> Date: Wed, 26 Mar 2008 16:37:17 EDT Subject: test To: email@example.com MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1206563837" X-Mailer: Unknown sub 34 X-Spam-Flag: NO test This e-mail account is for a client account made by ispconfig. I fixed outgoing mails but incoming e-mails get bounced. I've been working on this for days any help is appreciated.