Curate reporting to exclude non-MTA sources

This request is to provide an opportunity to filter out/clean up report data for sources like Enterprise Outlook, us.cloud-sec-av.com, ipw-outbound.inkyphishfence.com, nat.perception-point.io, etc that are following DMARC reporting standards but not actual MTA destinations. Such sources aren't enforcing DMARC policies, just reporting and as such, if excluded, reporting data would be much more accurate.