I just purchased this and it was simple and easy to get setup with a copy paste to the DNS record.

I have been planning on securing all of my domains setup with DMARK
Much cheaper than other competitors I've looked at that charge on a per domain basis.

Worked well and helped us to debug a DMARC issue we were having with deliverability.

We use many of the other DuoCircle products like autospf and tenant migration.

Another great product Brad, keep em' coming!