Deliverability Mastery

The deliverability mental model: one picture for authentication, reputation, content, and monitoring

Most deliverability guides cover one piece — SPF, DKIM, DMARC, BIMI, reputation, warmup — and assume you already know how the pieces fit. This is the picture they assume: how a mailbox provider decides whether your email reaches the inbox, what each acronym actually does inside that decision, and where to look first when placement tanks.

12 min read

IP warm-up in Braze — the playbook that actually holds

A fresh dedicated IP has zero reputation on day one. Most warm-up guides fixate on ramp speed and ignore the harder question — which users get the send each day. Here's the schedule, the Random Bucket Number trick, and the day-10 mistake that ruins most of them.

11 min read

SPF, DKIM, and DMARC explained for lifecycle marketers

Three DNS records decide whether Gmail trusts your marketing email or quietly bins it. Gmail and Yahoo made all three mandatory for bulk senders in 2024 and the grace period is over. This is the practitioner's explainer: what each record does in plain English, how they interact, and the setup order that won't accidentally block your own mail.

10 min read

BIMI and VMC: the verified-logo upgrade worth doing properly

BIMI puts your logo next to your mail in Gmail, Apple Mail, Yahoo and Fastmail. A Verified Mark Certificate adds the blue checkmark that signals your sender identity has been independently verified. Together they convert your DMARC investment into something every user can see — and for any program serious about brand and deliverability, the answer in 2026 is yes, do it.

10 min read

Google Postmaster Tools: a walkthrough for people who actually send email

Postmaster Tools is the single most valuable free deliverability tool and most programs either ignore it or misread the charts. Here's what each tab actually says, what to act on, and what to stop looking at.

9 min read

Incrementality testing: the measurement that tells you if a program actually works

Last-click attribution makes lifecycle look bigger than it is. Incrementality testing strips out users who would have converted anyway and surfaces the real number. This is how to design a test that produces a figure you can defend in front of a CFO.

9 min read

Attribution models for lifecycle: which one to defend in which room

Attribution debates are half epistemology, half politics. Last-touch is wrong but defensible. Multi-touch is more accurate but less defensible. Incrementality is the only one that answers the causal question — and it's the slowest. Here's which model to use for which question, and why.

10 min read

Reputation recovery: the 90-day playbook for dropping from High to Low

Domain reputation at Low or Bad isn't a problem you fix this week. It's a 6–12 week project of disciplined sending to engaged users only, while the reputation signals slowly reset. Here's the plan.

9 min read