IIS 7 URL Rewrite Rules Aren't Being Applied?

I have a .net 4.0 web application hosted on IIS7 server.

After reading this: [URL] about serving static content from another server, so that cookies aren't sent with every request for a static file, i tried it out but without much success.

This is the part written in the web.config file:

<system.webServer>
<rewrite>
<rules>
<rule name="images" stopProcessing="true">
<match url="^images/(.*)$" />
<action type="Rewrite" url="http://static-server.com/images/{R:1}" appendQueryString="true" logRewrittenUrl="true" />
</rule>
</rules>
</rewrite>
</system.webServer>

With this rule defined, every link to a file in the images folder should be rewriten into the static-server URL. But this doesn't work at all, now every image that is in the images folder returns a 404 not found. what could be causing this behavior or a different solution on how to serve files from a specific folder from a different server without having to go trough tons of code and change all the links to link to the static server?

I did also try using the Redirect action type instead of the Rewrite action, which actually worked, but it defies the reason why i'm trying to serve the files on a different server (this way the request is sent to my dynamic content server with all the required cookies and is redirected to the static-server which is actually worse than serving the images from the dynamic content server).