Email security is something every customer needs and almost none can run alone. That is a service you can package, monitor and bill.
Every domain needs the same controls watched: SPF, DKIM, DMARC and MTA-STS. DMARCER standardises that into an offering you can sell to your whole base, not a one-off project per client.
The monitoring, scoring and alerting run automatically, so the service doesn't eat your engineers' time. You add a line item your customers value and keep the margin.
