Best SPF Flattening Tools and Services in 2026: Honest Comparison
Quick Answer
The best SPF flattening tools in 2026 are AutoSPF (dedicated SPF flattening + macros, 15-minute re-scan, starts at $37/mo), PowerDMARC PowerSPF (hosted macros inside a full DMARC platform), MxToolbox Delivery Center (SPF flattening as part of a DNS diagnostic suite), DMARCLY Safe SPF (budget-friendly, simple interface), Redsift Dynamic SPF (enterprise real-time updates), Valimail Instant SPF (patented macro approach), and DMARCDuty DynamicSPF (free tier available). The right choice depends on whether you need dedicated SPF management or a full DMARC platform.
Related: How to Create an SPF Record ·SPF Record Format ·SPF Too Many DNS Lookups
SPF flattening solves the RFC 7208 10-DNS-lookup limit by replacing include: mechanisms with their resolved IP addresses, which consume zero lookups. Every modern business that uses 3+ email-sending services (Google Workspace, Microsoft 365, SendGrid, Mailchimp, Salesforce, HubSpot, etc.) eventually hits the 10-lookup wall — and SPF flattening is the standard fix.
This page compares the 7 most commonly evaluated SPF flattening tools. Full disclosure: AutoSPF is one of the options listed, and this page is published by AutoSPF. We’ve aimed to be honest about each tool’s strengths and weaknesses. If any characterization is inaccurate, contact us and we’ll correct it.
According to Google’s February 2024 bulk sender requirements, any domain sending 5,000+ messages per day to Gmail must authenticate with SPF, DKIM, and DMARC. A broken SPF record (PermError from exceeding 10 lookups) means SPF authentication fails for every message — making flattening a compliance requirement, not just a best practice.
What Is SPF Flattening and Why Do You Need It?
SPF flattening resolves every include:, a, mx, and redirect mechanism in your SPF record down to the underlying ip4: and ip6: addresses. Since IP-literal mechanisms consume zero DNS lookups, a flattened record can authorize dozens of sending services while staying well under the 10-lookup cap.
The catch: vendor IP ranges change. Google, Microsoft, and SendGrid all rotate their sending IPs periodically. A manually flattened record goes stale when this happens, silently de-authorizing legitimate senders. Every flattening tool listed below solves this by automatically re-resolving and re-publishing the flattened record on a schedule.
The alternative to flattening is SPF macros (RFC 7208 §7), which delegate per-query resolution to a dynamic DNS service. Macros bypass the 10-lookup limit entirely but require a managed service to operate. Some tools below offer macros as an alternative or complement to flattening.
How Does AutoSPF Compare?
AutoSPF — enterprise-grade SPF management (flattening + macros, SLAs, DPAs, NDAs, SSO/SAML, RBAC, audit logs, DNS rollback).
| Feature | Detail |
|---|---|
| Approach | Chained includes (flattening) on Plus; SPF macros on Premium/Enterprise |
| Re-scan frequency | Every 15 minutes |
| Pricing | Plus: $37/mo (1 domain) · Premium: $97/mo (5 domains, macros) · Enterprise: $387/mo (10 domains, SLA, SSO) |
| DMARC reporting | Via sister product DMARC Report (separate subscription) |
| What makes it different | SPF is the entire product, not a feature inside a DMARC platform. The 15-minute re-scan catches vendor IP changes faster than most competitors. Macros on Premium/Enterprise give unlimited includes without any lookup-limit concern. |
| Limitation | No built-in DMARC reporting in AutoSPF standalone (by design — keeps the SPF SLA independent). Sister product DMARC Report provides the combined platform for orgs that want everything together. |
| G2 rating | 5.0/5 (21 reviews) |
| Founded | 2018 · DuoCircle LLC · 2,000+ customers |
Best for: Enterprise organizations that need SPF solved with signed SLAs (99.99% uptime), DPAs, NDAs, SSO/SAML, RBAC/team management, audit logs, and DNS rollback — without migrating their existing DMARC stack. AutoSPF sits alongside your current tools; you don’t have to rip anything out.
How Does PowerDMARC PowerSPF Compare?
PowerDMARC — full DMARC platform with hosted SPF macros.
| Feature | Detail |
|---|---|
| Approach | Hosted SPF macros (PowerSPF) |
| Re-scan frequency | Varies by plan |
| Pricing | Check powerdmarc.com for current pricing (full DMARC platform pricing) |
| What makes it different | All-in-one dashboard: DMARC, SPF, DKIM, BIMI, MTA-STS, TLS-RPT. PowerSPF uses macros to bypass the 10-lookup limit within the platform. 10,000+ organizations, 100+ countries. |
| Limitation | SPF is one feature among many — if you only need SPF fixed, you’re paying for a full platform. Macro-based resolution depends on PowerDMARC’s DNS infrastructure being available at query time. |
| Founded | 2020 · ~40 employees · $4.1M revenue (2025, per GetLatka) |
Best for: Organizations that want DMARC + SPF + DKIM + BIMI managed from a single dashboard with a single vendor contract.
How Does MxToolbox Compare?
MxToolbox Delivery Center — the industry-standard DNS diagnostic platform.
| Feature | Detail |
|---|---|
| Approach | SPF flattening (Delivery Center Plus tier) |
| Re-scan frequency | Continuous monitoring |
| Pricing | Free tools tier + paid Delivery Center plans |
| What makes it different | Nearly two decades in the industry. 20+ diagnostic tools (SPF, DKIM, DMARC, blacklist, MX, SMTP). The broadest feature set of any tool in this space. |
| Limitation | SPF flattening is part of a broader platform — less specialized than dedicated SPF tools. The free tier is diagnostics only (no flattening). |
Best for: IT administrators who need a Swiss Army knife for all DNS and email diagnostics, with SPF flattening as one capability.
How Does DMARCLY Safe SPF Compare?
DMARCLY — budget-friendly DMARC + SPF platform.
| Feature | Detail |
|---|---|
| Approach | Safe SPF (hosted flattening) |
| Pricing | Competitive pricing — check dmarcly.com |
| What makes it different | Straightforward interface designed for beginners. Lower price point than most competitors. Good for organizations with simpler SPF configurations. |
| Limitation | Less specialized for complex, high-include-count scenarios. Fewer enterprise features (no macros, limited SLA options). |
Best for: Small businesses and teams new to email authentication who need a budget-friendly solution without enterprise complexity.
How Does Redsift Dynamic SPF Compare?
Redsift OnDMARC — enterprise email security platform with dynamic SPF.
| Feature | Detail |
|---|---|
| Approach | Dynamic SPF — maintains a single optimized record that auto-updates in real time |
| Pricing | Enterprise-tier pricing — check redsift.com |
| What makes it different | Real-time IP change detection. Strong engineering reputation. Part of a broader email security and brand protection platform. |
| Limitation | Enterprise pricing reflects a full-platform approach. If you only need SPF solved, it’s heavy. |
Best for: Large enterprises that want SPF management integrated with broader email security, brand protection, and compliance.
How Does Valimail Instant SPF Compare?
Valimail — patented macro-based SPF solution.
| Feature | Detail |
|---|---|
| Approach | Instant SPF — patented SPF macro technology |
| Pricing | Enterprise-tier — check valimail.com |
| What makes it different | Patented macro approach that’s technically distinct from competitors’ implementations. Strong regulatory compliance credentials. Free SPF checker available alongside the paid platform. |
| Limitation | Enterprise pricing and positioning. The patented approach creates vendor lock-in — your SPF record depends on Valimail’s macro resolver. |
Best for: Enterprise organizations with strong compliance requirements that want a differentiated, patented approach to SPF management.
How Does DMARCDuty DynamicSPF Compare?
DMARCDuty — lightweight SPF flattening with a free tier.
| Feature | Detail |
|---|---|
| Approach | Automatic SPF flattening |
| Pricing | Free tier available — check dmarcduty.com for paid plans |
| What makes it different | Has a genuinely free tier for basic SPF flattening. Simple, no-frills approach without the enterprise overhead. |
| Limitation | Smaller company with less feature depth. Limited support and SLA options. |
Best for: Budget-conscious teams or individuals who want basic SPF flattening without a paid subscription.
Side-by-Side Comparison Table
| Feature | AutoSPF | PowerDMARC | MxToolbox | DMARCLY | Redsift | Valimail | DMARCDuty |
|---|---|---|---|---|---|---|---|
| Primary approach | Flattening + macros | Hosted macros | Flattening | Hosted flattening | Dynamic SPF | Patented macros | Flattening |
| SPF-dedicated | Yes (enterprise SLA) | No (full platform) | No (full platform) | No (DMARC+SPF) | No (full platform) | No (full platform) | Yes |
| Re-scan frequency | 15 min | Varies | Continuous | Varies | Real-time | Real-time | Varies |
| Free tier | Free checker tool | Free checker tool | Free diagnostics | Free checker | No | Free checker | Yes (flattening) |
| Macro support | Premium+ | Yes | No | No | No | Yes (patented) | No |
| Enterprise SLA | 99.99% | Check vendor | Check vendor | No | Check vendor | Check vendor | No |
| DMARC built-in | No (sister product) | Yes | Yes | Yes | Yes | Yes | Yes |
| Starting price | $37/mo | Varies | Varies | Budget-friendly | Enterprise | Enterprise | Free |
| G2 rating | 5.0/5 | Check G2 | Check G2 | Check G2 | Check G2 | Check G2 | Check G2 |
Which SPF Flattening Tool Should You Choose?
| Your situation | Recommended tool |
|---|---|
| Enterprise SPF with SLA + compliance docs (DPA/NDA/SSO/SAML), keep existing DMARC stack | AutoSPF |
| Want everything (DMARC+SPF+DKIM+BIMI) in one platform | PowerDMARC or Redsift |
| Need broad DNS diagnostics + SPF flattening | MxToolbox |
| Budget-conscious, simpler SPF setup | DMARCLY or DMARCDuty (free) |
| Enterprise with strict compliance requirements | Valimail |
| Need SPF macros for unlimited includes | AutoSPF Premium or PowerDMARC or Valimail |
Related Reading
- free SPF checker tools
- PowerDMARC alternatives
- SPF record examples for common vendor combos
- SPF too many DNS lookups
The critical action is getting your SPF record under the 10-lookup limit so authentication actually works. Per RFC 7208 §4.6.4, exceeding 10 lookups produces a PermError that fails SPF for every message from the domain. Whichever tool you choose, fix this before the next email you send.
CEO
Founder and CEO of DuoCircle. Product strategy and commercial lead for AutoSPF's 2,000+ customer base.
LinkedIn Profile →Fix your SPF record in 60 seconds
Try AutoSPF free for 30 days. No credit card required.
Start Free Trial