We started SimpleDMARC 5 years ago to make DMARC implementation less painful for IT teams and MSPs managing multiple domains. What began as a monitoring tool has grown into a full email authentication platform — and today we shipped a complete rebuild.
The new version includes 30+ free tools covering the full email authentication stack:
— DMARC: record checker, generator, policy validator, alignment analyzer
— SPF: record checker, generator, flattener (for the 10-lookup limit problem)
— DKIM: key validator, selector checker, rotation helper
— BIMI: record validator, VMC checker, logo preview
— MTA-STS: policy generator, validator, TLS-RPT checker
— Diagnostics: email header analyzer, phishing URL checker, blacklist checker
Everything is free, instant, no account required. We built these because we kept needing them ourselves and nothing free was specific enough about what was actually wrong.
The thing that frustrates us most about existing DMARC tools: they tell you something is failing but not which sending source, not why the alignment is broken, and not what an attacker can actually do with your current policy. Ours tries to answer all three.
Technical stack if anyone's curious: Vue 3, Fastify, PostgreSQL, BullMQ for report processing, AWS Route 53 for DNS automation.
Happy to go deep on DMARC implementation, SPF flattening edge cases, DKIM rotation without breaking mail flow, or anything else email authentication. Five years of edge cases means we've probably seen your problem before.
Implementing DMARC for companies using multiple SaaS tools (CRM, marketing automation, helpdesk, etc.) often becomes messy because each provider needs SPF/DKIM alignment. Curious if your tool helps visualize which services are properly aligned versus failing.
This is such a wonderful tool as dmarc is something which is not that much known to the people. It is one of the best ways to protect your email. I think this tool is offering 30 free email authentication tools. I strongly recommend and will keep using the same. Thank you very much.
Curious how this fits into a DevOps workflow. Is there an API or CLI integration that allows teams to automatically validate DMARC/SPF/DKIM configs during CI/CD when infrastructure changes are deployed?
The tooling looks useful, but one challenge with these diagnostics platforms is keeping DNS checks fast when records contain many nested includes. Curious how you’re handling performance for complex domains.
DMARC debugging becomes painful when multiple vendors send email on behalf of the same domain. Does your alignment analyzer help identify which specific source is causing DMARC failures in aggregate reports?
Email spoofing is still surprisingly common even with DMARC adoption increasing. Tools that help organizations verify configuration quickly can probably reduce a lot of phishing risk.
With more SaaS platforms sending transactional and marketing emails, email authentication is getting increasingly complex. Tools that simplify debugging are becoming pretty essential.
One pain point with SPF is the 10 DNS lookup limit defined in the specification. Does your SPF flattening tool help prevent lookup overflow when multiple services are included?
This looks useful. Have you considered adding automated DMARC report visualization so users can quickly see which IP ranges or services are failing authentication?