Measuring email from the other end

The story begins in early 2014, with an idea: read a brand's email campaigns like a series. Its sending frequency, its peak moments through the year, its strongest promotions and when they land. A web marketing tool, designed to compare brands against each other — and it already rested on the same foundations: subscribe to their newsletters, archive every email, and read what it contains, from size to links to trackers. The project was called Newslistr. Development began that summer; the entry point was already a free diagnostic.

The project sat in a drawer, with its mockups, its pitch and its two hundred subscriptions. The foundations, though, hadn't aged.

In spring 2026, the CNIL published its recommendation on tracking pixels in emails. It comes down to one question, asked email by email: does this tracker need the consent of the person receiving the message? Sending platforms announced new settings, brands described their practices. Seen from outside, none of it could be verified without asking. And the drawer held exactly what it took to verify.

We reopened it in 2026, and rewrote everything: the same gesture now served a different question. No longer “what are the competitors doing”, but “what actually arrives, and can it be proven”. The raw message is archived as is, never modified. Analyzers read it without loading or clicking anything — the pixel, the links, unsubscribing, authentication, then the rest —, each one versioned, each one replayed across the whole archive when it changes. That's what lets us redo, today, an identical finding from yesterday.