That is again something different - you seem to be talking about “anonymous contacts” (you may want to research that term), with the switch enabled they will still be created but as “*.*.*.*"
Oh then there’s a misunderstanding here. My original question was how to stop Mautic from creating contacts with only IP addresses. You are saying the “anonymous contacts” toggle has nothing to do with it, is that correct?
There is no “anonymous contacts” toggle…
The ”Anonymize IP” toggle, though, is almost what you want:
It prevents the IP to be stored.
It does NOT prevent anonymous contacts from being created - they just no longer carry the IP address.
If you want to really get rid of anonymous contacts (and again, make sure to first understand what they are good for!): Best practice is to
create a segment with filter “email address = EMPTY”
create a campaign starting from that segment that does nothing but “delete contact”.
(DANGER ZONE, obviously. Make double sure to not accidently delete contacts that you would rather keep.)