Kann bei thunderbird keine Mails verschicken (yahoo)

Hi leute!
Sorry schon mal im vorraus fals es diesen Thread schon irgendwo gibt aber ich hab nix dazu gefunden 😉
Mein Problem: wenn ich bei Thunderbird Mails mit meiner Yahoo-Adresse verschicken will kommt eine Nachricht zurück das es einen Fehler gab

Hi. This is the qmail-send program at yahoo.com.
I\’m afraid I wasn\’t able to deliver your message to the following addresses.
This is a permanent error; I\’ve given up. Sorry it didn\’t work out.

:
194.25.134.72 does not like recipient.
Remote host said: 550 5.1.1 user unknown
Giving up on 194.25.134.72.

— Below this line is a copy of the message.

Return-Path:
Received: (qmail 77663 invoked from network); 2 Dec 2006 19:16:13 -0000
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024; d=yahoo.de;
h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:Content-Type:Content-Transfer-Encoding;
b=wXgnXFugsrxZDNb2PaglPPIAYLlQp/sFglqXNFc8T0kGLIOvQZzElDaMIK/WbrhdmlhenhXqt+pOZHhE2yvdwlv93xZmj/TH5FGN54qZzLZqOMp1KS1MzUqyUbFxbwImgTJ16lkIHvRf6tV5YYfFPMVF4TNTpXBAgtjafGLBDTc= ;
Received: from unknown (HELO ?192.168.1.33?) (xxxx@84.58.0.240 with plain)
by smtp007.mail.ukl.yahoo.com with SMTP; 2 Dec 2006 19:16:13 -0000
X-YMail-OSG: Xsj4DrAVM1k4ecpcK7zQdEICFt.wDMGvBV1KpzYF4YdokoltuaE7F5Np6V2VhPbQTaojCN.lcJez1QA1Cuw_
Message-ID:
Date: Sat, 02 Dec 2006 20:16:13 +0100
From: xxxxxxxxxxxxxt@yahoo.de>
User-Agent: Thunderbird 1.5.0.8 (Windows/20061025)
MIME-Version: 1.0
To: xxxxxxxxxx@t-online.de>
Subject: (kein Betreff)
Content-Type: text/plain; charset=ISO-8859-15; format=flowed
Content-Transfer-Encoding: 7bit

Vielleicht hilfts euch ja!
Danke schonmal im Vorraus
MFG Sergnant 🙂