✉️SPF, DKIM & DMARC Record Generator Documentation & Guide

Web & Developer

Sender Policy Framework (SPF) and Domain-based Message Authentication, Reporting, and Conformance (DMARC) form the cornerstone of enterprise email defense. Mandated by Google, Yahoo, and Microsoft for all bulk and business senders, these protocols authenticate legitimate mail transfer agents (MTAs), prevent spoofing and business email compromise (BEC), and grant administrators actionable aggregate telemetry (RUA) over unauthorized senders.

📋How to Use This Tool

Select Configuration Mode: Use Record Generator to build brand-new records or Syntax Validator to inspect an existing TXT snippet for RFC errors.
Configure SPF Authorized Sendering: Specify your sending providers (e.g. _spf.google.com, sendgrid.net) and IPv4 relays, choosing between ~all (SoftFail) and -all (HardFail).
Set DMARC Enforcement Policy: Select an enforcement posture (p=reject for zero spoofing tolerance, or p=quarantine for spam filtering) and configure your reporting address.
Publish to DNS: Click ✉️ Generate DNS Records and copy the DNS TXT records directly into your authoritative DNS host (Cloudflare, AWS Route 53, Namecheap).

⚙️RFC Specifications & The 10-Lookup Ceiling

Email authentication engines enforce strict operational invariants:

• SPF 10-Lookup Limit (RFC 7208 Section 4.6.4): Senders are strictly capped at 10 DNS queries across include, a, mx, and redirect mechanisms. Exceeding 10 triggers an immediate PermError and drops deliverability.

• DMARC Alignment (RFC 7489): DMARC requires that the domain in the visible From: header aligns with the authenticated SPF domain or DKIM signing domain (d=).

• SoftFail vs. HardFail: Modern DMARC implementations recommend ~all for SPF because DMARC overrides SPF failures, and strict -all can break legitimate mail forwarders lacking SRS (Sender Rewriting Scheme).

💡Practical Use Cases & Best Practices

2024 Google & Yahoo Compliance: Senders emailing more than 5,000 daily messages must enforce DMARC with at least p=none and have aligned SPF and DKIM.
Parked & Defensive Domains: For domains that never send email, publish a null SPF record: v=spf1 -all and DMARC: v=DMARC1; p=reject to eliminate impersonation.
Subdomain Inheritance: DMARC policies apply recursively to subdomains unless overridden by a specific sp= tag (e.g. sp=reject).

100% Client-Side Privacy Guarantee:All SPF parsing, lookup evaluations, and DMARC policy generation execute purely in your local browser sandbox. Zero domain names, provider keys, or email reporting addresses are sent to external networks.

SPF, DKIM & DMARC Record Generator