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DomainPreflight vs SPFToolbox
SPFToolbox handles SPF lookups and WHOIS. DomainPreflight covers the full email authentication stack — SPF, DKIM, DMARC alignment, IP reputation, dangling records, and typosquat monitoring — in one browser tool.
Key differences
- SPFToolbox: SPF / MX / WHOIS focus
- DomainPreflight: full stack + alignment + deliverability extras
Both open source
SPFToolbox and DomainPreflight are open-source friendly. You can read the checks and run them locally.
Where SPFToolbox wins
- Single-purpose SPF lookup depth
- Lightweight if you only care about SPF strings
Where DomainPreflight wins
- DMARC alignment and provider detection
- DKIM probes, blocklists, typosquat, dangling records
- One workflow for “why is mail failing?”
Walk the full SPF tree + alignment in Preflight
Open DNS Preflight →FAQ
How do features overlap?
Both help with SPF. DomainPreflight adds DKIM, DMARC alignment, IP reputation, and non-SPF DNS tools in the same UI.
Does SPFToolbox cover DMARC alignment?
It doesn't focus on alignment scoring — DomainPreflight does, including provider-specific CNAME gaps.
Are both open source?
Yes — DomainPreflight is MIT on GitHub. SPFToolbox is open source in spirit; verify its license on the project page.
Which tool should I use for SPF flattening?
Use SPF lookup depth to see includes — DomainPreflight's tree helps you see lookup count before you flatten. Pair with vendor IP docs.
Should I use both?
If you want a second opinion on raw SPF text, sure. For most teams, DomainPreflight alone covers SPF plus the rest of the stack.