About InboxStack
Built to end the guesswork.
Brain was born out of a simple frustration — email deliverability was a black box, and everyone was guessing. We built the intelligence layer that finally opens it up.
Why we built this
Email teams were drowning in data — starving for answers.
The metrics existed. The signals were there. But the infrastructure to connect them — to turn raw numbers into a clear picture of what was failing and why — simply didn't.
ESP metrics without context
Bounce rates and complaint percentages were reported in isolation, with no way to know what was driving them or which campaigns were responsible.
Provider signals scattered across tools
Gmail Postmaster, Microsoft SNDS, and DNS data lived in separate dashboards — requiring manual cross-referencing to spot patterns.
No correlation between data sources
Even teams with access to all the right data had no way to connect an authentication failure to a reputation drop to a deliverability event — the dots were never joined.
Fixes based on guesswork, not diagnosis
Without a clear root cause, teams applied generic best-practice changes and hoped something worked — burning time and often making things worse.
Our answer
Three capabilities that replace guesswork.
Each one is built to do exactly one job, well — and they work together to give you a complete, actionable picture of your deliverability.
Signal Engine
Every signal in one feed.
Brain ingests ESP campaign data, Gmail Postmaster, Microsoft SNDS, and DNS records into a single unified engine. Every data point is timestamped, correlated to a domain identity, and fed into a continuous analysis pipeline — so nothing gets reviewed in isolation.
RCA Inspector
Trace every drop to a root cause.
Brain traces why your performance changed, not just that it did. When signals cluster around an event, the causal-graph engine isolates the originating failure from its downstream symptoms — with precision no dashboard can replicate manually.
Resolution Center
A specific fix, not a checklist.
Once the root cause is identified, Brain generates a prioritised fix sequence specific to your infrastructure — your ESP, your sending domains, your authentication setup. Every step is ranked by expected impact, so you always know where to start.
Our conviction
Every email team deserves to know exactly what's happening, why, and what to do about it — without needing a deliverability PhD.
No black boxes
Every signal, every score, every recommendation is explainable. You always see the reasoning behind what Brain tells you.
No generic advice
Brain's playbooks are generated from your actual data and infrastructure — not templated checklists that apply to every program the same way.
No guessing
Every fix Brain recommends is grounded in correlated signal evidence — not intuition, not convention, not a best guess.
Who we are
A small team obsessed with email infrastructure.
We're engineers, deliverability veterans, and product thinkers who have spent years watching email programs fail for reasons that were entirely preventable. Misconfigured authentication records. Reputation signals that went undetected for weeks. Root causes buried inside noise that no one had time to untangle. The same avoidable failures, over and over again.
Brain is what we wish had existed when we were on the other side of this problem. We built it because the tools available to email teams were either too shallow to be useful, or too complex to use without a specialist on staff. That gap shouldn't exist. So we closed it.
See it in action
Connect your ESP. Brain takes it from there.
The first signals appear within hours. The first incident, within days. Stop diagnosing fires — start preventing them.