Thanks Christian Santiago — Email status exists on contacts but isn't available in dashboard widget filters yet. We're looking at bringing widget filters in line with Smart List filters.

Stopgap for now: in Smart Lists, filter Email status = Invalid, select all, and bulk-add a tag (e.g. email-invalid), then filter your widget by that tag. Note that the tag won't update automatically if the status changes.

What are you looking to report on — reachable contacts, excluding bad leads, something else?