InboxStack watches Gmail, Outlook & Yahoo for your domain, flags what needs a closer look, and keeps a timestamped history behind every alert. We do the watching. You make the call.
Takes 60 seconds. No credit card required.
Built for every sender. Sized for agencies & ESPs.
Two audiences, one engine. Self-serve for senders. White-label-ready for the platforms that serve them.
Senders and marketing teams get the same view of Gmail, Outlook and Yahoo that a full-time email engineer builds by hand, without the complexity or the Validity price tag.
One client's emails in spam is a churn risk for the whole account. Brain watches every customer domain at scale, so you act before the customer notices.
Customer results
Not generic praise — specific incidents caught and resolved.
InboxStack Brain flagged a reputation issue before it hit inbox rates. The RCA Inspector pointed straight to the problem and we fixed it the same morning — without paging an engineer.
The Causal Graph shows us exactly what broke and why. Our clients see better inbox rates and we spend far less time firefighting deliverability across the agency portfolio.
The Signal Engine caught an SPF issue that was silently tanking our Outlook delivery — we'd never have spotted it ourselves. Brain told us why it was happening and exactly what to fix.
How it works
No log diving. No spreadsheet exports. No consultant on retainer. Brain handles the diagnosis end to end.
Plug in your ESP via API or webhook. Brain starts pulling live performance signals immediately and sets your baseline at Gmail, Outlook and Yahoo.
When a signal deviates, the RCA Inspector runs the diagnosis. SPF or DKIM failures, a drop in how Gmail scores your domain, and provider-specific rejections map to a clear verdict in under 4 minutes.
The Resolution Center turns the diagnosis into a prioritized playbook for your exact situation. You apply the fix; Brain confirms the recovery.
The problem
Most tools tell you something is wrong. They show you a red light. No context. No cause. No plan. No fix.
Most platforms flag failures hours or days after they begin — by then, the damage is done.
Without a cause to start from, every investigation is a shot in the dark that costs days of engineering time.
Each provider rejects for different reasons — fixing one without knowing the cause can make the others worse.
Advice disconnected from your actual infrastructure and sending history helps no one.
The solution
Before you send, when something breaks, and every day in between: Brain covers all three.
Know where the send lands before you press send.
From the first odd number to the cause to the fix in under 4 minutes.
Hands-off hygiene that runs while you sleep.
Connectors & data sources
Brain pulls real performance data from your ESP — not the estimates competitors run on. Then we layer in Google Postmaster, Microsoft SNDS, DMARC reports, DNS audits, and 50+ blocklists. Every diagnosis runs on full evidence.
See it in action
The alert system
Every send is checked as it goes out. Brain classifies the deviation, traces the chain of events, and surfaces the exact fix.
Daily check
Gmail, Outlook, and Yahoo broken out separately — per IP, per domain, per stream. Catch a Yahoo-only drop before anyone files a ticket.
The war room
Multi-domain senders stop pivoting between dashboards. Every sending identity in a single live view, prioritized by revenue impact.
Pre-send seed test
Drop your draft into Brain. We seed-test across Gmail, Outlook, Yahoo, and Apple in seconds — and tell you exactly which providers will reject it before your audience does.
The diagnosis
Every diagnosis cites the signals it's based on: header changes, SPF and DKIM changes, content fingerprints, list churn, IP warmup state.
