The 2026 Deliverability Benchmark
What 400 million sends across 6,200 domains tell us about Primary placement, reply rates by sequence length, and which signals actually predict a spam slide before it happens.
Reply Rate Falls Off A Cliff At Step Five
Replies climb steadily to step four, flatten at five and go slightly negative after that once you account for complaints. The fifth email is the last one worth sending.
Six Findings Worth Acting On
The ones that changed how we configure defaults.
Small lists reply 3× better
Campaigns under 1,000 contacts averaged 11.4% replies. Over 10,000, that fell to 3.4%. Specificity beats reach by a wide margin.
Open tracking costs placement
Domains sending with tracking pixels landed in Primary 6.8 points less often than matched domains sending without.
Complaint rate predicts collapse
Crossing 0.08% complaints preceded a placement drop within nine days in 74% of cases. It is the earliest reliable signal.
Tuesday is not special
Send-day differences were under one percentage point once volume was controlled for. Send when your prospects work.
DMARC enforcement helps
Domains on p=quarantine or stricter placed 4.1 points better in Primary than those on p=none.
Breakup emails work
The final step in a sequence out-replied step two in 38% of campaigns. Ending well matters more than opening cleverly.
About The Data
Method, scope and what we deliberately excluded.
Where does this come from?
Aggregated, anonymised sending data from Outfrank accounts across 2025. No individual account, contact or message content is identifiable in any figure quoted.
What was excluded?
Accounts under 1,000 lifetime sends, domains in their first 14 days of warmup, and any account flagged for abuse. All three skew the numbers badly.
How is placement measured?
Seeded mailboxes we own across 14 providers, read directly. Not inferred from opens, which privacy proxies make close to meaningless.
Can I get the raw data?
Not the underlying sends, for obvious reasons. We will share the aggregated tables behind every chart if you are writing something up — just ask.
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