2 articles
Complete guide to email-related DNS records: MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, PTR. Each record explained with concrete examples.
Everything about email encryption: STARTTLS, opportunistic vs enforced TLS, MTA-STS, DANE, TLS-RPT. Why Gmail shows a red padlock and how to avoid it.