E-mail problem

Hello. Never had problems with the post, but I installed everything again and started to have problems. How do I send email from another account, get the return, here's the text:

This is the mail system at host server.kurdak.eu. 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 <kurdak@debian> (expanded from <kurdak@kurdak.eu>): Host or domain name not found. Name service error for name=debian type=A: Host not found Reporting-MTA: dns; server.kurdak.eu X-Postfix-Queue-ID: B8D841924D9 X-Postfix-Sender: rfc822; kurdak@plusnet.pl Arrival-Date: Wed, 25 Mar 2009 22:58:03 +0100 (CET) Final-Recipient: rfc822; kurdak@debian Original-Recipient: rfc822;kurdak@kurdak.eu Action: failed Status: 5.4.4 Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error for name=debian type=A: Host not found Temat: Re: TEST Nadawca: kurdak <kurdak@plusnet.pl> Data: Wed, 25 Mar 2009 22:58:11 +0100 Adresat: kurdak@kurdak.eu kurdak@kurdak.eu pisze: > TEST > >

/etc/hostname [code:1]debian[/code:1] /etc/hosts [code:1]127.0.0.1 localhost 192.168.0.111 debian.kurdak.eu debian[/code:1]

PLEASE HELP ME