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Perspectivas técnicas sobre entregabilidad de correo, endurecimiento de infraestructura y diseño con enfoque en privacidad.

The Email Deliverability Landscape in 2026

Google, Yahoo, and Microsoft now require SPF, DKIM, and DMARC for all commercial senders. Here's what changed and what it means for your infrastructure.

deliverability authentication DMARC

Postfix TLS: Beyond Opportunistic Encryption

Most mail servers support TLS but don't enforce it. DANE, MTA-STS, and proper protocol configuration close the gap between "encrypted sometimes" and "encrypted always.

TLS DANE MTA-STS Postfix

febrero 27, 2026

SPF, DKIM, DMARC, and ARC: The Complete Authentication Stack

Email authentication is no longer optional. Here's how the four protocols work together — and why ARC is critical for anyone who forwards mail.

SPF DKIM DMARC ARC authentication

febrero 12, 2026

SRS: Why Forwarded Email Breaks SPF and How to Fix It

When you forward an email, SPF fails. The Sender Rewriting Scheme fixes this — and without it, forwarded mail from strict domains gets rejected.

SRS SPF forwarding Postfix

Spam Filtering Architecture: Milters, Bayes, and Greylisting

Authentication proves mail is legitimate. Spam filtering proves it isn't malicious. Here's how to architect a filtering stack that protects deliverability.

spam Rspamd Bayes greylisting milter

Rate Limiting and Abuse Prevention for Mail Servers

Connection floods, brute-force attacks, and spam bursts all hit the SMTP port. Here's how to stop them at multiple layers without blocking legitimate mail.

rate limiting abuse prevention Postfix Fail2ban

diciembre 27, 2025

DNS Security for Email: DNSSEC, DANE, and Local Resolvers

DNS is the foundation of email authentication. If your DNS can be spoofed, SPF, DKIM, and DMARC are all meaningless. Here's how to secure it.

DNS DNSSEC DANE Unbound

diciembre 10, 2025

Monitoring Your Mail Stack: Proving It Works

A correctly configured mail server that silently stops processing mail is worse than a misconfigured one. Here's how to monitor every layer and catch failures before users do.

monitoring Monit operations deliverability