Rewritemap for static rewrites

Rewritemaps.config

<rewriteMaps>
  <rewriteMap name="nlRewrites">
	  <add key="/" value="https://www.newdomain.eu/nl"/>
		<add key="/het-bedrijf" value="https://www.newdomain.eu/nl/over-ons/"/>
		<add key="/producten/lamp value="https://www.newdomain.eu/nl/producten/verlichting/lamp"/>
  </rewriteMap>
</rewriteMaps>

    

web.config

<rewrite>
  <rules>
	  <rule name="Old nl urls">
		  <match url=".*" />
			<conditions>
			  <add input="{HTTP_HOST}" pattern="^(.*)?.domain.nl$" />
				<add input="{nlRewrites:{PATH_INFO}}" pattern="(.+)" />
			</conditions>
			<action type="Redirect" url="{C:1}" appendQueryString="false" redirectType="Permanent"/>
		</rule>
  <rules>
<rewrite>

This works in my environment. Unfortunately this is without Umbraco, and I cannot reproduce your domain.nl / newdomain.eu structure, but that shouldn't matter. I redirect within one site.

`

  <rules>
    <rule name="Redirect rule for rewrite map">
      <match url=".*" />
      <conditions>
        <add input="{go:{PATH_INFO}}" pattern="(.+)" />
      </conditions>
      <action type="Redirect" url="{C:1}" appendQueryString="false" />
    </rule>
  </rules>

  <rewriteMaps>
    <rewriteMap name="go">
      <add key="/" value="https://example.com" />
      <add key="/test" value="servervars.aspx" />
    </rewriteMap>
  </rewriteMaps>

</rewrite>

`

Perhaps browser cache? I always use something like curl/wget on the commandline to test redirects.