October 3, 20266 min read
Inbox Placement Tests: Gmail, Outlook & Yahoo Explained
Your 'delivered' rate lies. Placement tests show where emails actually land — inbox, spam, or nowhere. Here's how to run them right.
Most senders watch 'delivered' rates and assume everything is fine. But 'delivered' only means the receiving server accepted the message — it says nothing about whether it landed in the inbox, the spam folder, or the promotions tab.
An inbox placement test answers the real question. You send your actual campaign email to a set of seed inboxes you control — real Gmail, Outlook and Yahoo accounts — then check where each copy landed.
Run the test before every major campaign, and again after any change: new domain, new copy, new links, new sending volume. A placement test takes minutes and can save a whole campaign.
How to read results: 90%+ inbox across seeds is healthy. If Gmail is inbox but Outlook is spam, your issue is likely content or link reputation, not domain reputation. If all seeds miss the inbox, stop sending and fix authentication (SPF, DKIM, DMARC) first.
Common gotchas: testing with the same seed too often trains the seed (use fresh seeds for clean signal), and rescuing a test email from spam biases future results for that seed.
Vexrim Outreach runs placement tests from the Deliverability page: pick a campaign, add seed inboxes, send, and watch inbox vs spam results roll in — with full history so you can prove deliverability is improving over time.