Inbox placement rate is the percentage of your delivered emails that actually reach the inbox, rather than the spam or junk folder. It is a sharper measure than delivery rate: an email can be accepted by the server (delivered) yet still be filtered to spam, where it is rarely seen.
Placement rate vs delivery rate
Delivery rate counts messages the receiving server accepted; inbox placement rate counts those that landed in the inbox. The gap between them is your spam-folder problem. Authentication, reputation, and engagement drive placement — see email authentication and sender reputation.
How to improve it
Authenticate your domain, mail engaged opt-in contacts, keep complaints and bounces low, and watch your deliverability score. Mailpro's email statistics and authenticated sending help your mail reach the inbox. Read the email deliverability guide. Related: deliverability.
Mailpro and deliverability
Reach the inbox, not the spam folder
Authenticated, Swiss-hosted sending and reputation monitoring lift your inbox placement so your campaigns get seen.