OK, I understand now. You want to offer this as a service to check spam trap checking for email addresses. I dont know if it would be feasible to ship a list of 7 million email addresses with a mautic installation. Also that list of spam traps may change over time, not sure if you are planning to update it.
Speaking about list hygiene, there are probably additional tests that should be made to ensure that an email address is really valid.
Not quite sure yet on where you see your part in the picture. Maybe you could set up an email validating service with an API that allows sites to check whether an email is valid or not. Then there would be a need for a Mautic plugin that can connect to the API and query the validity of emails on the list, or even check email validity right on the signup form.
It would be surely possible to write a plugin that has a local list as well. The question is just how the maintenance of the list would be managed. And surely proper validating of an email involves much more than just spam traps. Not sure what would be involved to do this all within a plugin.
I was already thinking it would be nice to have a plugin to connect to an existing Email verification service. For example https://www.ipqualityscore.com/ . They are giving 5000 API requests per month for free. That could be good enough for most sites. If you have more than 5000 signups per month, you can probably afford to pay for their services.