Local mail system with gmail on Fedora 20

edit

Can someone please explain why I get this message when I send mail to: root@localhost from my system. I've set up gmail on it to send mail and forwarded root's mail to my gmail.

Error message:

Delivery to the following recipient failed permanently:

     root@localhost

Technical details of permanent failure: 
DNS Error: Domain name not found              <-------------- I just noticed this, is this the problem, how do I resolve this?

----- Original message -----

Algorithm here; Some values here;
        d=gmail.com; some value here;
        h=message-id:from:date:to:subject:user-agent:mime-version
         :content-type:content-transfer-encoding;
        key here
X-Received: by 10.181.11.133 with SMTP id here;
        Sun, 28 Sep 2014 23:14:44 -0700 (PDT)
Return-Path: <hk.stefansson@gmail.com>
Received: from Hostname (My ip here and more)
        by mx.google.com some id
        for <root@localhost>
        (Algirthm values here);
        Sun, 28 Sep 2014 23:14:44 -0700 (PDT)
Message-ID: <some id.google.com>
From: root <hk.stefansson@gmail.com>
X-Google-Original-From: "root" <root@Hostname>
Received: by Hostname (sSMTP sendmail emulation); Mon, 29 Sep 2014 06:14:42 +0000
Date: Mon, 29 Sep 2014 06:14:42 +0000
To: root@localhost
Subject: This is a test
User-Agent: Some agent
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: some coding

Test

I configured the system with this.

I send a test message with this command:

echo Test | mail -s "This is a test" root@localhost

Is it because gmail is trying to send a mail to root@Hostname with gmail and can't find the recipient, if so how can I fix this so gmail understands who root@Hostname is?