Authentication
What is DMARC Policy?
The instruction in a DMARC record (none, quarantine, or reject) telling receivers how to handle mail that fails authentication.
The DMARC policy is set by the p tag in the _dmarc TXT record and takes one of three values: none for monitor-only, quarantine to treat failing mail as suspicious (often the spam folder), or reject to block it outright. An optional pct tag applies the policy to a fraction of failing mail, and the sp tag sets a separate policy for subdomains. Receivers apply the policy to messages that fail DMARC alignment and authentication.
Why it matters for cold email
Bulk-sender rules from Google and Yahoo require at least p=none, but tightening to quarantine or reject after monitoring protects your domain from spoofing that would otherwise wreck deliverability. Cold senders should start at none, read the aggregate reports, authenticate every legitimate source, then move the policy up.
Related terms
Stop guessing at deliverability.
Scheduler Zero handles authentication, warmup, and sender reputation so your cold email lands in the inbox, not the spam folder.