The Deliverability Benchmark
What 20 million emails a month reveal about how mail actually lands — measured from real inboxes across the Warmup Inbox network, not seed-list tests.
Seven benchmarks that change how you run deliverability
Every figure comes from real mail flowing to real inboxes — placement no seed list can see. Here are the findings that matter most.
The Gmail measurement gap
Standard IMAP reports a 98.9% inbox rate. Measured honestly through OAuth, the true primary-tab rate is 88.7%. The gap is tab routing, not spam.
Warmup is done in two weeks
Not the folklore eight. Median inbox rate hits 95% in week 1 and 98% by week 2 — but it only holds while warming continues, like the gym.
Gmail is the canary
When placement degrades, Gmail reacts first 84.7% of the time — and hardest. Make it your primary KPI.
The 15-day recovery cliff
Duration beats depth. Catch a drop early and recover in a week; let it sit past day 15 and recovery time jumps ~8×.
Two myths that don't move placement
Domain age (r = −0.10) and send-day (0.4pp spread) barely register. A fresh domain is not a handicap.
Only 1 of 4 Gmail policies mattered
Across 3.7 years, only the Nov 2025 enforcement ramp left a clear network signal — and it recovered in ~16 weeks.
Everything is a race against day 15
A severe drop caught in three days recovers about as fast as a mild one. The variable that predicts recovery is not how far you fell — it's how long you stayed down.
The analysis behind the numbers
In 3.7 years, only one Gmail policy change actually mattered
Why the recurring policy panic is mostly noise — and what the real inflection points were.
Read the articleWhy duration beats depth in reputation recovery
The full breakdown of the cliff, from 71,581 real degradation events.
Read the articleThe Reputation Recovery Playbook
What to do when placement drops — the first 72 hours, the closing window, and life after day 15.
Read the articleYour 99% Gmail rate is counting folders, not tabs
How honest OAuth measurement changes the deliverability picture.
Read the articleRun the benchmark on your own inboxes
Where does your mail actually land?
See your real primary-vs-tabs-vs-spam split by provider, measured the honest way, in minutes.
Run the free testCatch a drop before day 15
Check your domain and IP reputation against major blocklists so you can act while recovery is still fast.
Check your reputationSee these benchmarks on your own inboxes
Connect an inbox to the network of 20,000+ real inboxes, watch placement climb, and get alerted the moment reputation slips — while recovery is still fast.
Deliverability Benchmark Report 2026 · Figures reflect the Warmup Inbox network as of May 2026. Correlations do not establish causation.