Compare
DomainPreflight vs MXToolbox
MXToolbox tells you what's wrong. DomainPreflight tells you how to fix it — with copy-paste DNS records, provider-specific alignment detection, and no account required.
Comparison
| Feature | MXToolbox | DomainPreflight |
|---|---|---|
| DMARC alignment check | Basic | Deep — detects per-provider CNAME gaps |
| Copy-paste DNS fix | ❌ | ✅ |
| No signup required | ⚠️ Partial | ✅ Always |
| Client-side only | ❌ | ✅ |
| DMARC XML analyzer | ❌ | ✅ |
| Typosquat monitor | ❌ | ✅ |
| Dangling record scan | ❌ | ✅ |
| DNS propagation check | ✅ | ✅ |
| Pricing | Freemium ($19/mo) | Free always |
| Open source | ❌ | ✅ MIT |
Where MXToolbox wins
- Brand recognition and trust (20+ years)
- Monitoring alerts (paid tier)
- Broader tool coverage (HTTP checks, etc.)
- Larger historical database
Where DomainPreflight wins
- Alignment engine: detects provider-specific CNAME issues MXToolbox misses
- Copy-paste fixes: not just flags — actual DNS records to paste
- No account ever: nothing stored, nothing tracked
- DMARC XML analysis: paste your report, see what's failing
- Open source: inspect every check
Run DNS Preflight — alignment, SPF tree, and more
Open DNS Preflight →FAQ
Is DomainPreflight a free alternative to MXToolbox?
Yes — all DomainPreflight tools are free with no account required. MXToolbox has a free tier but limits lookups and requires signup for full access.
What does DomainPreflight do that MXToolbox doesn't?
The alignment engine detects provider-specific CNAME gaps — MXToolbox tells you DMARC fails but not why SendGrid specifically is breaking alignment.
Does MXToolbox have monitoring alerts?
Yes — MXToolbox charges $19/mo for scheduled monitoring. DomainPreflight is manual scan only currently.
Which tool should I use first?
Run DomainPreflight first — it gives you actionable fixes, not just flags. If you need ongoing monitoring, consider MXToolbox's paid tier later.
Is DomainPreflight open source?
Yes — MIT licensed at https://github.com/metriclogic26/domain-preflight. MXToolbox is proprietary.