[saintamh]

Domain search is free. I never paid for HIBP and they give me a list of every address @my-domain that’s been leaked.

Edit: others are pointing out that it’s only free for domains with fewer than 10 pwned addresses. I have 8.

[fencepost]

The message I got wasn't related to the number of addresses affected (though I've been using this approach for a couple decades), but IIRC regarded whether the datasets in question were free.