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Articles and tutorials on communication infrastructure.

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61–69 of 69 articles

Authentication Deliverability Infrastructure Protocols

The ARC Header: How Forwarding Breaks DMARC and What You Can Do

Forwarders break DMARC by modifying messages in transit. ARC (RFC 8617) preserves authentication results across hops. How it works, who supports it, and the limits.

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David

Oct 24, 2023

Deliverability Strategy

Content Filtering and Spam Scoring: What Still Trips the Filters

Content rules decide far less than reputation, and they still reject mail on their own. What rule-based scoring measures, what Bayesian filters learn, and what to fix.

DavidSep 19, 2023

Protocols Authentication

BIMI Explained: Is the VMC Investment Worth It for B2B Senders?

BIMI displays your logo in supporting inboxes. The VMC certificate costs $1,500/year. Whether the brand recognition lift justifies the spend honestly assessed.

DavidAug 22, 2023

Deliverability Infrastructure

Why Your Transactional Emails Are Landing in Spam (And Mixing Them with Marketing Is The Reason)

Password resets going to spam? You're sending them from the same IP and domain as marketing campaigns. The four operational fixes that actually work.

DavidJul 25, 2023

Infrastructure Deliverability

IP Warming in 2023: A 30-Day Schedule That Actually Works

Most IP warming schedules fail because they ignore engagement segmentation. The 30-day ramp that actually works volume tables, segment ordering, and recovery rules.

DavidJun 13, 2023

Infrastructure Deliverability

The Hidden Cost of Shared IP Pools (And When to Move to Dedicated)

When to move from shared to dedicated IP pools. The volume threshold, reputation contamination risks, and the cost-benefit analysis ESPs don't want you to do.

DavidMay 9, 2023

Protocols Authentication

Understanding DMARC Policies: From p=none to p=reject Without Breaking Things

How to move from DMARC p=none to p=reject without breaking production mail. The phased rollout that actually works with the failures most senders hit.

DavidApr 18, 2023

Authentication Protocols

DKIM Explained: How a Signature Proves the Mail Is Yours

SPF authorises servers, DKIM authenticates messages. How the signing and verification cycle works, what each tag in the header does, and where signatures break.

DavidMar 21, 2023

Authentication Protocols

SPF Records Demystified: Why Your "v=spf1" Setup Is Probably Wrong

Most SPF records are subtly broken. The 10-lookup limit, multiple records, +all, and the alignment trap what's actually wrong with your SPF setup.

DavidFeb 14, 2023