What this DMARC builder produces:
Fill in your domain and policy settings on the left, then click Generate DMARC Record to build:
p=, sp=, rua=, and alignment rules.Explore Other Free Diagnostics
Simulate mobile inbox truncation and optimize cold email subjects.
Verify SVG Tiny-PS logos, VMC certificates, and DMARC alignment.
Detect throwaway domains and temporary MX mail infrastructure.
Highlight spam triggers and swap in inbox-safe phrasing.
DMARC Record Generator FAQs.
Understand how to safely roll out DMARC from monitoring mode to strict enforcement without blocking legitimate emails.
Which DMARC policy should I start with?
Start with p=none alongside a valid rua=mailto: reporting address for 2 weeks. Once your reports confirm all legitimate senders pass SPF and DKIM, upgrade to p=quarantine and finally p=reject.
Do Google and Yahoo require DMARC?
Yes. Both Google and Yahoo require bulk senders to publish at least a valid DMARC record (v=DMARC1; p=none;) aligned with SPF or DKIM to avoid delivery throttles and spam placement.
What is the difference between Relaxed (r) and Strict (s) alignment?
Relaxed alignment (r, the default) allows subdomains like mail.company.com to match your main company.com From address. Strict alignment (s) requires an exact domain match.
Clean your entire email list with zero bounces.
Sortwell checks addresses the way a mail server would — live SMTP handshake, syntax, MX verification, and spamtrap detection.