Use p=none and collect rua reports until all legitimate senders are known.
DMARC Record Generator
Create a DMARC TXT record for email authentication with policy, reporting, alignment, and rollout controls.
DMARC settings
DNS output
DNS record typeTXT
Record length69
Report URIs1
EnforcementMonitoring
Domain is ready
Publish this TXT record at the _dmarc host for the domain.
Aggregate reporting enabled
rua reports help you monitor legitimate and failing email sources.
Start with monitoring
p=none is safest while you validate SPF, DKIM, and legitimate senders.
TXT length is OK
The record is within the common 255-character DNS TXT string limit.
Rollout guide
Apply quarantine to a small pct first, then increase as failures are resolved.
Move to reject after SPF/DKIM alignment is stable and reports look clean.