Simple definition
Alignment DMARC checks that the domain visible in From corresponds to the domain authenticated by SPF or DKIM.
Technical definition
Alignment DMARC checks that the domain visible in From corresponds to the domain authenticated by SPF or DKIM. In the business environment, its configuration must be consistent with the network architecture, security policies and capabilities of the equipment concerned.
What is it used for?
reduce the usurpation of the sender domain.
Practical example
DKIM sign with the same domain as the To.
Common issues
- Inconsistent configuration
- Compatibility or version
- Incomplete dependency diagnosis
Key takeaway: Always adapt the diagnosis to the product version and the architecture actually deployed.