Porbleme gmail et thunderbid

Bonjour j'ai un problème avec ma boite email gmail :
j'envoie des messages qui n'arrivent pas au destinataire et j'ai cet email en retour :
Sujet: Delivery Status Notification (Failure)
De: mailer-daemon@gmail.com
This is an automatically generated Delivery Status Notification

Delivery to the following recipient failed permanently:

adresse correspondant

Technical details of permanent failure:
PERM_FAILURE: SMTP Error (state 10): 550 5.1.1 adresse correspondant... User unknown

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

Received: by 10.54.33.2 with SMTP id g2mr7210060wrg;
Tue, 30 Aug 2005 06:47:11 -0700 (PDT)
Return-Path: mon adresse
Received: from ?192.168.0.1? ( [82.251.8.147])
by mx.gmail.com with ESMTP id 16sm3190366wrl.2005.08.30.06.47.10;
Tue, 30 Aug 2005 06:47:11 -0700 (PDT)
Message-ID: <4314635F.5010300@gmail.com>
Date: Tue, 30 Aug 2005 15:47:11 +0200
From: mon adresse
User-Agent: Mozilla Thunderbird 1.0 (Windows/20041206)
X-Accept-Language: fr, en
MIME-Version: 1.0
To:
Subject: le sujet
Content-Type: multipart/mixed;
boundary="------------020201050209050306020605"

This is a multi-part message in MIME format.
--------------020201050209050306020605
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8bit

le message

--------------020201050209050306020605
Content-Type: text/plain;

----- Message truncated -----

Que faire ?
Merci