Email Inbox Placement Guide

Inbox placement rate (IPR) measures what percentage of your emails actually reach the primary inbox, as opposed to the spam/junk folder or being rejected outright. Achieving consistent inbox placement requires getting multiple factors right simultaneously.

The inbox placement hierarchy

1. 1

   Authentication (SPF, DKIM, DMARC)

   These records prove your email is legitimately sent from your domain. Without them, your message may be rejected before any content-based filter even runs.

2. 2

   Sender Reputation

   Your sending IP and domain accumulate a reputation score based on bounce rate, spam complaint rate, and engagement. A new sending domain needs to warm up gradually before high-volume sending.

3. 3

   List Quality

   Sending to invalid addresses and spam traps damages your sender reputation regardless of your content quality. Regular list hygiene is essential.

4. 4

   Content Quality

   Spam trigger words, poor HTML structure, and high image-to-text ratio all contribute to lower inbox placement scores. Addressing content issues is the fastest way to improve scores for an established sender.

5. 5

   Recipient Engagement

   Gmail and Outlook track whether recipients open, click, and reply to your emails. High engagement improves your inbox placement over time, while consistently ignored emails are increasingly likely to be filtered.