AutoSPF vs DynamicSPF (by Dmarcduty): The Ultimate SPF Flattening Showdown

Email authentication is no longer optional—it’s a frontline defense against phishing, spoofing, and business email compromise (BEC). One of the cornerstones of authentication is the Sender Policy Framework (SPF). But as organizations grow, add third-party senders (like Microsoft 365, Google Workspace, Mailchimp, Salesforce, Zendesk, etc.), and layer in new services, their SPF records often hit a major roadblock:

“The 10-lookup limit is the single most common reason enterprise SPF records silently break,” says Brad Slavin, CEO of DuoCircle and founder of AutoSPF. “In our experience managing SPF for 2,000+ customer domains, the failure mode is always the same: a team adds a new SaaS tool, its include pushes the total past 10, and legitimate email starts failing.”

Per RFC 7208, SPF evaluation is capped at 10 DNS mechanism lookups and 2 void lookups per check — exceeding either limit produces a PermError that fails authentication for every message from the domain.

Partial The 10 DNS lookup limit.

Exceed this, and SPF breaks—leading to “permerror” failures, weakened DMARC alignment, and potential delivery issues.

This is where SPF flattening tools step in. Two of the most talked-about solutions are:

AutoSPF – an automated SPF flattening and management platform.
DynamicSPF by Dmarcduty – a DNS-driven, dynamic approach to SPF optimization.

But which one is right for your business? Let’s dive deep.

Why SPF Flattening is Critical

Before comparing AutoSPF and DynamicSPF, let’s clarify why flattening matters:

SPF Lookup Limits – Each “include” in SPF counts as a DNS lookup. With multiple vendors, hitting 10 lookups is easy. Beyond that, SPF fails.
Dynamic IP Ranges – Email providers frequently change or expand their sending IPs. A static SPF record quickly becomes outdated.
Deliverability & DMARC – Broken SPF records weaken DMARC policies, causing emails to land in spam—or worse, get rejected.
Admin Overhead – Manually updating SPF is unsustainable for teams with multiple domains or third-party services.

Flattening condenses all the “include” lookups into a single, optimized record that respects SPF’s limits—ensuring your emails authenticate properly.

How Does AutoSPF Compare to DynamicSPF: Head-to-Head?

AutoSPF – Automated SPF Flattening for Hands-Off Compliance

AutoSPF is built for organizations that want set-and-forget SPF management. It continuously monitors, flattens, and updates your SPF record in real-time.

Key Features

Fully Automated Flattening – Resolves all includes into IPs without exceeding the 10-lookup limit.
Continuous Monitoring – Detects when providers (like Google or Microsoft) update IP ranges and updates your SPF automatically.
Error Prevention – Eliminates “permerror” failures that break DMARC compliance.
Dashboard & Reporting – Centralized portal for managing multiple domains.
Enterprise Scalability – Supports portfolios of 10, 100, or even 1,000+ domains.

Best For: SMBs, enterprises, and MSPs that need reliability and automation without dedicating engineering hours to SPF upkeep.

DynamicSPF (by Dmarcduty) – Real-Time SPF Resolution

DynamicSPF takes a different approach. Instead of flattening once and pushing a static record, it uses DNS-based dynamic responses to return optimized SPF data on-the-fly.

Key Features

DNS-Driven Responses – SPF records are generated dynamically when queried.
Advanced Customization – Flexible setup for admins who want fine-grained control.
Technical Depth – Geared toward IT/security teams with DNS expertise.
Reduced Manual Updates – Still requires proper DNS configuration and oversight.

Best For: Power users, managed security providers, or organizations with dedicated IT teams who want more control than a fully automated service provides.

Feature-by-Feature Comparison

Category	AutoSPF Yes	DynamicSPF (Dmarcduty) ⚡
Automation	100% automated SPF management	Semi-automated, DNS-driven
Ease of Use	Web dashboard, no DNS skills needed	Requires DNS expertise
Compliance	Always DMARC/SPF compliant	Depends on admin accuracy
Scalability	Handles 1 to 1,000+ domains easily	Better suited to fewer domains
Risk of Breakage	Extremely low (self-correcting)	Higher if DNS misconfigured
Ideal User	IT teams seeking simplicity	Security pros who want control

Pricing & Value

AutoSPF: Predictable subscription-based pricing, with tiers for startups, SMBs, and enterprise. Free trials available for smaller domains
DynamicSPF (by Dmarcduty): Pricing often varies depending on customization and organizational needs. Best value for teams already comfortable managing DNS.

Verdict: AutoSPF is more cost-effective for most businesses due to lower admin overhead. DynamicSPF appeals to power users who already invest in DNS management.

Real-World Use Cases

🔹 AutoSPF in Action

A SaaS startup using Google Workspace, SendGrid, HubSpot, and Zendesk quickly hit SPF lookup limits. AutoSPF automatically flattened records and kept them up to date—no IT intervention required.
A managed service provider (MSP) overseeing 50+ client domains consolidated SPF management into AutoSPF’s dashboard, eliminating hours of monthly manual updates.

🔹 DynamicSPF in Action

A cybersecurity consultancy with dedicated DNS engineers deployed DynamicSPF to retain more granular control over SPF behavior.
An enterprise with complex, global DNS infrastructure used DynamicSPF to tailor SPF responses for different regions.

Alternatives Beyond AutoSPF & DynamicSPF

If you’re exploring SPF flattening, a few other approaches exist:

Manual SPF Flattening – Copying resolved IPs into your SPF record. Works short-term, but breaks when IPs change.
SPF Macros – Advanced, but complex and not widely supported. Risky for most orgs.
DMARC Suites (Valimail, PowerDMARC, Agari, etc.) – Offer SPF management as part of larger DMARC compliance packages. Typically priced for enterprises.

Final Verdict: Which Should You Choose?

Both AutoSPF and DynamicSPF help solve SPF’s lookup limit problem—but their philosophies differ:

Choose AutoSPF if you want automation, zero maintenance, and guaranteed compliance. It’s the right choice for 90% of organizations.
Choose DynamicSPF if you’re a technical power user with in-house expertise who wants to control SPF behavior at the DNS level.

👉 Bottom line: For most businesses, AutoSPF is the safer, simpler, and more scalable solution.

FAQs: AutoSPF vs DynamicSPF

Q: Why not just flatten SPF manually?A: Manual flattening becomes outdated quickly when providers change IPs. AutoSPF automates updates.

Q: Does SPF flattening improve email deliverability?A: Yes. By ensuring SPF passes, flattening prevents “permerror” failures that weaken DMARC alignment.

Q: Which is better for enterprises with multiple brands/domains?A: AutoSPF—its centralized dashboard and automation scale across large portfolios.

Q: Does DynamicSPF require special DNS setup?A: Yes. It relies on dynamic DNS responses, which require technical expertise and ongoing monitoring.

Q: Can AutoSPF and DynamicSPF work together?A: In theory, yes, but they solve the same problem differently. Most orgs should standardize on one approach.

Yes Recommendation: Start with AutoSPF if you want automation, peace of mind, and immediate DMARC compliance. Consider DynamicSPF if you’re a security-heavy enterprise with DNS expertise and a need for advanced customization.