What is Inbox?

With ISPs like Gmail blocking 10 million potentially harmful emails every 60 seconds, it’s no surprise that mailbox providers have applied aggressive filtering measures to protect their customers and deter spam. As a result, legitimate senders need sophisticated real-time tools to help them land in the inbox and know when they don’t. Emails that don’t reach the inbox are wasted opportunities.

With Inbox, we focus on tracking this “last mile” of measuring your inbox placement, not just deliverability. The international seed coverage helps you track inbox placement around the world and deliver real-time feedback to help you pinpoint deliverability issues and take corrective action.

Inbox consists of several screens:


The Campaigns screen provides a performance overview of your recent seed list tests. Any campaign can be clicked to view individual campaign results.

Seedlist Optimizer

By uploading a segment of your mailing list, the Seedlist Optimizer (patent pending) provides you with a personalized, weighted seedlist for more accurate deliverability testing.

Get Seedlist

Here you can find the most up-to-date seedlist and instructions on how to copy your list.

ISP Health

The ISP Health Dashboard helps identify ISP-specific service issues across the 250ok community and answer questions like, “Is there a problem at Yahoo! today,” or, “Is everyone having this issue or just me?”

Creating an Inbox Test

This includes instructions on how to copy your seedlist and create your first test.