Create an app extension that helps identify unwanted messages.
To create a Message Filter app extension, add a target that uses the Message Filter Extension template to the Xcode project for your containing app. The principal view controller in your app extension is a subclass of
ILMessage that adopts the
If you have servers that can help your app extension determine how to handle a message, you must add the Associated Domains capability to your Xcode project and specify those domains. Then, you must set up shared credentials as described in Shared Web Credentials, substituting
webcredentials throughout the steps. Lastly, you must specify the domains in your
Info file, which should look similar to the dictionary shown below.