Using “New to Universe” lets you target phones or emails that have recently been added to Switchboard. The creation date is based on when the phone or email is first added to Switchboard through CSV upload, NGPVAN import, ActBlue donation, or form submission.

Using this New to Universe filter with an Engagement filter allows you to target new phones or emails that have not yet received an email. You can use this in a saved search that will dynamically update. Do note that if you have scheduled sends with filters like this, uploading a CSV or running a large NGPVAN import may drastically increase the audience.