<div>
I don't know, sorry but i'm not an expert. How can I check that ?<br />
When I make a pop account in outlook without exchange server, It's working.
</div>


I don't know, sorry but i'm not an expert. How can I check that ?
When I make a pop account in outlook without exchange server, It's working.

<div>
Solution was the FAI who blacklist our domain name. Now it's working. Thanks for your help...
</div>


Solution was the FAI who blacklist our domain name. Now it's working. Thanks for your help...

<div>
Finally I found where was the problem... Domain name was blacklisted...
</div>


Finally I found where was the problem... Domain name was blacklisted...

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<div class="content wysiwyg-content">
Hi since this morning we cannot send email anymore with <br />
immediately returned email with this message: <br />
&nbsp;<br />
(sorry it's in french...)<br />
<br />
Problème de communication SMTP avec le serveur de messagerie du destinataire. Contactez votre administrateur système.<br />
&nbsp; &lt;themalingua.be #5.5.0 smtp;553 #5.1.8 Domain of sender address &lt;user (at) themalingua.be&gt; does not exist&gt;<br />
<br />
Everything is ok in the recipient policies and default adress is the good one<br />
Also we have the problem with all user mailboxes<br />
We are using smtp connector with pop3 connector...<br />
internal email is working<br />
<br />
<br />
Please help ! Tell me what informations you need.
</div>
</div>


Hi since this morning we cannot send email anymore with 
immediately returned email with this message: 
 
(sorry it's in french...)

Problème de communication SMTP avec le serveur de messagerie du destinataire. Contactez votre administrateur système.
  <themalingua.be #5.5.0 smtp;553 #5.1.8 Domain of sender address <user (at) themalingua.be> does not exist>

Everything is ok in the recipient policies and default adress is the good one
Also we have the problem with all user mailboxes
We are using smtp connector with pop3 connector...
internal email is working


Please help ! Tell me what informations you need.

Unable to send email using smtp connector

Small Business Server (SBS) is a line of server operating systems targeted at small businesses by bundling the operating system with a number of other Microsoft products that would normally need to be purchased or licensed separately. The most notable inclusions are Exchange, SQL Server, SharePoint and ISA/TMG (Microsoft's firewall and proxy server).

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.