TL;DR
ListKit doesn't show an inbox health or reputation score. Judge your inboxes by your campaigns' replies.
A reply rate above 1% (all replies) means your emails are reaching people. The main result to aim for is 1 positive reply per 1,000 people contacted.
Judge each campaign angle after about 1,000 people contacted, not after a few days.
If positive replies fall and the reply rate drops below 1%, check your list, copy and bounces before blaming the inboxes.
When you'd use this
Use this when replies have dropped and you're worried an inbox is burned, or when an older guide mentions a Warm-Up Reputation Score you can't find.
How to check inbox health
Open the Analytics page (or the Campaign page) and look at each campaign's replies and reply rate.
Check that the campaign has contacted at least about 1,000 people. Earlier numbers move around too much to judge.
If the reply rate is above 1% and you are getting positive replies, your inboxes are healthy. Keep sending.
If the reply rate is below 1% and positive replies have dropped, check the bounce rate and your list quality. See Why is my bounce rate high and how do I fix it?
Still not sure? Message us with the campaign name and we'll take a look.
Earlier versions of ListKit showed a Warm-Up Reputation Score. It only measured the background warmup network, not your real campaigns, and it is no longer shown.
Expected outcome
You know whether an inbox needs attention, based on the results that matter: replies and positive replies.
FAQ
Where is the Warm-Up Reputation Score or health score?
ListKit no longer shows one. Use your campaign reply rate and positive replies instead.
Is my inbox burned?
Probably not if its campaigns keep a reply rate above 1%. Look at falling positive replies together with bounces and list quality.
Should I pause my campaign if replies dip for a few days?
Not on its own. Wait until the campaign has contacted about 1,000 people, then judge it. See What should I expect from my ListKit campaigns in the first 90 days?
What should I do if my reply rate drops below 1%?
Check your targeting, your copy and your bounce rate. See Why aren't my cold email campaigns performing, and how do I fix them?