ShieldMarc's recommendation: don't ramp by percentage (pct=). Ramp by sender confidence.
The pct= trap
Many older guides say "set pct=10, then 25, then 50". This silently drops 10-50% of legitimate mail without telling you which senders are affected. Customers can lose mail for weeks before noticing.
The report-driven path we recommend
- 1. Stay at p=none until DMARC reports show all your legitimate senders aligned at >99%
- 2. Move directly to p=quarantine. Watch reports for 7-14 days.
- 3. If alignment stays >99% and no legit senders are quarantined, move to p=reject.
How long should each step take
Most domains can move from p=none to p=quarantine in 4-8 weeks once they're aligned. Quarantine to reject is typically another 2-4 weeks. ShieldMarc emails you when alignment is high enough to safely take the next step.