Hey fellow self-horders!
I built mailcheck — a free, open-source tool that checks all 6 email authentication protocols (SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI) for any domain and gives you a 0–100 deliverability score.
Try it: https://korpo.pro/ — type any domain and get instant results.
Self-host it: It’s MIT licensed with a FastAPI backend. pip install mailcheck or clone from our Forgejo repo.
CLI: mailcheck example.com — great for CI/CD integration (exit code 2 on critical issues).
API: curl https://korpo.pro/api/v1/check/example.com — no auth needed, 100 req/hr.
Batch mode: mailcheck --file domains.txt
I found that many well-known domains have misconfigurations — even big crypto projects. The tool helped me fix my own domain’s email auth setup.
Would love feedback from email/infra folks!
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
1 acronyms in this thread; the most compressed thread commented on today has 6 acronyms.
[Thread #256 for this comm, first seen 26th Apr 2026, 04:30] [FAQ] [Full list] [Contact] [Source code]