IIS App Pool Permissions
This is one of those things that I don’t do very often so I end up having to look it up. The issue comes about when you create a new site on newer versions of IIS. You set it all up and get hit by a permissions issue. This has always been a bane of IIS but now it’s made trickier to resolve unless you know this trick.
I’m going to assume that you know how to setup a site and an app pool. In my case I have something like this
I’ve setup the Postbox site and an app pool for it to use but when I try to browse the site I get a permissions error. As you can see the app pool is running under the ApplicationPoolIdentity but that’s not available as a user to assign permissions to. The answer to this is that the accounts created by the app pool are not exposed in the normal way, you need to add a prefix and the system will find the user and handle it as expected. The prefix is IIS AppPool\ so in my case the search needs to be for
IIS AppPool\Postboxthen everything will work as normal, when you click on check names it will be recognised
Now your site should work as expected.