<div>
Can you paste the full NDR message?
</div>


<div>
Because I had to change some DNS configurations
</div>


Because I had to change some DNS configurations

<div>
<div class="content wysiwyg-content">
I´m guetting an error 421 5.5.0 whem sending messages &nbsp;from an exchange2007 to a exchange 2003 behind a ISA2004, In the ex2003 side i´m able to receive mail from others exchange´s 2007 , any clue?
</div>
</div>


I´m guetting an error 421 5.5.0 whem sending messages  from an exchange2007 to a exchange 2003 behind a ISA2004, In the ex2003 side i´m able to receive mail from others exchange´s 2007 , any clue?

I´m guetting an error 421 5.5.0 whem sending messages  from an exchange2007

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.