@kensanata You might want to check this very informative talk about modern email security. I saw it live at #fossgbg
http://conf.tube/videos/watch/376e1487-4cf6-42f0-a470-aed3a6d3becd
There are also free services that provide DMARC weekly aggregate reports. E.g.: https://dmarc.postmarkapp.com/ (have not checked their privacy policy)