The warm-up record: see how every inbox was warmed before you buy it

Warm-up, briefly

A brand-new inbox on a brand-new domain has no sending history, and mailbox providers are cautious with senders they know nothing about. Warm-up builds that history: the inbox sends and receives a modest, steady amount of mail every day, and the volume grows gradually. Over a few weeks the domain and the inbox earn a reputation, so that when real campaigns start they are not judged as a complete unknown.

The guide on how inbox warm-up works covers the mechanics and the usual timelines. This page is about something narrower: how you can tell whether an inbox you are about to buy was actually warmed.

The problem with "pre-warmed"

When you buy pre-warmed inboxes you are buying time that someone else spent. The trouble is that the time is invisible. An inbox warmed carefully for a month and one switched on last week can be sold with the same word, and you only learn which one you bought once your campaigns start bouncing or landing in spam.

When we reviewed 5 pre-warmed inbox providers in October 2026, none showed per-domain warm-up stats before purchase. So every domain InboxesNow sells comes with its warm-up record, and you see it before anything goes in your cart.

What the warm-up record shows

The record has four parts, for every domain on sale.

Days warmed

How many days the domain has been warming. Nothing goes on sale with fewer than 21 days, and the record shows the exact number, so a domain at day 31 is distinguishable from one that has just reached the minimum.

The daily warm-up chart

Every day of warm-up, drawn as bars: how many warm-up emails were sent that day and how many of them reached the inbox. Where the sent bar shows above the inbox bar, some of that day's warm-up mail missed the inbox. A steady run of full bars is what you want to see; repeated gaps are worth noticing.

The 7-day warm-up inbox rate

The share of the last seven days' warm-up email that reached the inbox, as one number. It is the quickest way to compare domains, and it is what Auto-pick best uses when you let the shop choose for you.

The health score

A single warm-up health score for each domain, shown beside the rate and the chart. Read it together with the chart rather than on its own: the chart shows you the days behind the summary.

Reading the example above

The record at the top of this page is an example, with sample numbers, but it reads the same way a real one does. Start with the days warmed: the domain is past the 21-day minimum, and the strip beside the number fills from cold to warm as the days add up. Then look at the daily chart. Most days, the inbox bar reaches the top of the sent bar, which means that day's warm-up mail reached the inbox; on the few days where a sliver of the sent bar shows above it, some mail missed. The 7-day warm-up inbox rate turns the last week of those bars into one number, and the health score sits beside it as a single summary for the domain. A record like this, long, steady and with few gaps, is what a well-warmed domain looks like. A short history, a chart with frequent gaps, or a rate that is falling are all reasons to pick a different domain.

How to read it

• Look at the length and the shape together. Plenty of days with a steady chart is a stronger sign than a high rate over a short history.
• Compare like with like. When choosing between domains, compare the same window: the 7-day rate of one against the 7-day rate of another.
• Remember what warm-up measures. Warm-up mail is not a campaign to your prospects. It shows the inbox has been active and well received while it warmed, not how your own campaigns will perform.

Read it next to the placement record

The warm-up record tells you how an inbox was warmed. The inbox placement record tells you where its mail lands today. Every inbox in stock gets a placement test every day, sending to seed inboxes at Google Workspace, Outlook and Gmail in the US and recording whether each message reached the inbox, a category tab or spam, and whether SPF, DKIM and DMARC passed. A long, steady warm-up with consistent placement is the profile to look for.

After you buy

The record describes the domain's history up to the moment you buy it. What happens next depends on how you send:

• Into Instantly, the inboxes move into your workspace with one Google sign-in each, verified on the delivery board. See pre-warmed inboxes for Instantly.
• Into any other sequencer, you release the domain and connect each inbox yourself with Google sign-in. Our warm-up of those inboxes stops the moment you release them, so if you want warm-up to continue, turn it on in your sequencer. See pre-warmed inboxes for any sequencer.

Either way, start your campaigns at a modest volume. By default each inbox sends up to 30 campaign emails a day, alongside its warm-up.

What it costs

Each domain is 3 inboxes for $15 a month ($5 per inbox), with the domain included and no setup fee. The warm-up record is part of every domain, not an extra. See pricing for the planner.

Related

For the terms used here, see the deliverability glossary. For what every domain includes, see pre-warmed Google Workspace inboxes.