Marketing / Lifecycle
Inbox Placement Rate IPR (aka 'inbox rate'; contrast delivery/accepted rate)
Whether your email actually reached the inbox, not merely whether the receiving server accepted it.
The fork, why two teams get different numbers
"Deliverability" names two very different measurements.
In the Metric Library
- The full fork, both definitions worked all the way through
- The trap that makes the number lie, on a real export
- Every formula variant, spelled out
- The reconciliation anchor, what to tie it to and when to refuse
Reference: M3AAWG deliverability guidance (reference) ยท DMARC/SPF/DKIM authentication standards (reference)