Koltrix
Guides
dig commands every email engineer should know
The dig queries that answer most email questions: SPF, DKIM selectors, DMARC, MX, PTR, MTA-STS and BIMI, plus how to bypass caches when testing.
5 min read
- Guides
Testing SMTP by hand with swaks and openssl
Talk to a mail server directly to see what it really says. Use swaks and openssl s_client to test auth, TLS, relaying and rejections step by step.
5 min read