Inbox Placement
Also known as: Inbox Placement Rate, IPR
Inbox placement is the share of sent messages that land specifically in the recipient's primary inbox, as opposed to spam, promotions tab, social tab, or quarantine. It is a stricter metric than delivery rate (which counts any accepted message) and more useful as the actionable deliverability indicator in 2026.
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Inbox placement is the metric every email-sending team should be reporting on but most do not. The sending platform usually reports "delivered" for any message the receiving server accepted, which is delivery rate. Inbox placement is the share of those delivered messages that reached the recipient's primary inbox.
How to measure
Inbox placement cannot be directly measured per recipient (you do not see where the email landed in their inbox unless they tell you). Seed-list testing is the standard approach: send a copy of the campaign to a known panel of test inboxes across Gmail, Microsoft 365, Yahoo, Apple, and others. Tools like GlockApps, MailReach inbox tests, and Postmark seed tests automate this.
What drives inbox placement
The same factors that drive deliverability overall: authentication (SPF, DKIM, DMARC), domain reputation, IP reputation, content patterns, engagement signals. Inbox placement is the metric these factors most directly influence.
Typical inbox placement rates
Mailbox providers don't publish placement rates, and seed-list tests from different vendors disagree, so treat any single benchmark with care. What you control: authentication that passes, a domain that's been warmed up, a verified list, and spam complaints under Google's 0.1 percent. If placement drops on a seed test, check authentication and content patterns first.
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Start Free TrialFrequently asked questions
Is inbox placement the same as delivery rate?+
No. Delivery rate counts any accepted message including those that land in spam. Inbox placement counts only messages that reached the primary inbox.
How often should I test inbox placement?+
Weekly for high-volume senders; monthly for moderate-volume. After any deliverability incident (sender reputation drop, content change, IP migration), test immediately.
Put this concept into practice
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Related glossary terms
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We update these pages when the underlying mechanics change. new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.