Deliverability
What is Inbox Placement?
The share of delivered emails that land in the primary inbox rather than spam or a secondary tab.
Inbox placement rate (IPR) measures where accepted mail is actually filed by the receiving provider. Unlike delivery rate, which only confirms server acceptance, IPR separates the primary inbox from spam/junk and category tabs. Because providers do not report per-recipient placement, it is typically estimated using seed lists of test accounts across providers or via panel data.
Why it matters for cold email
A cold campaign can show a 99% delivery rate while most messages sit in spam, so inbox placement is the number that actually predicts replies. Running seed tests before scaling exposes provider-specific filtering (Gmail versus Outlook, for example) so you can fix reputation or content problems before burning through your prospect list.
Related terms
Stop guessing at deliverability.
Scheduler Zero handles authentication, warmup, and sender reputation so your cold email lands in the inbox, not the spam folder.