This section in the User Guide has some details: Configuring Restrictive User Account and Passphrase Settings

We don't use the geolocation content filter. We have it set up on the Host Access Table (HAT) on the Public Listener. We've added particular geolocations to the Blocklist. Using the content filters was using up too much CPU for emails we didn't want ...

You need to create a dictionary and use it in a Content Filter or a message filter that checks for Body Content matches.Add your URL into the dictionary using regex. EG: ((?i)example\.domain\.com). If you get an error when adding it, type a random st...