Prewarmed inboxes and domains for cold email
51 days of reputation.
Yours today.
Gmail and Outlook do not trust a new domain. We age and warm it 51 days so you can send today — Google Workspace, Microsoft 365 or Azure.
Orders are placed on Warm Inboxes, run by the same team as this site.
The 2026 Prewarmed Standard for Maximum Deliverability
What prewarmed means here
Proper accounts
Real Google and Microsoft accounts, not a relay service or a shared seat.
30 days of age
A domain’s age cannot be faked or rushed, and Gmail and Outlook both check it.
21 days of warming
Three weeks of real emails sent and replied to, so the domain has a track record.
Ready the same day
You get the logins within hours. The 51 days of waiting already happened.
Pick your provider
Prewarmed Google inboxes
Real Google Workspace accounts on an aged domain. Same day.
View →Prewarmed Microsoft 365 inboxes
Licensed Microsoft mailboxes, best for Outlook-heavy lists.
View →Prewarmed Azure tenants
100 mailboxes in one account. For high volume.
View →Not starting for two months? Each one has a fresh version — cheaper, and you run the 51 days.
Fresh Google Fresh Microsoft 365 Fresh Azure tenants Fresh domains
Prewarmed, fresh or do it yourself
| Prewarmed | Fresh inbox | Do it yourself | |
|---|---|---|---|
| How soon you can send | Same day | 21 days on a domain you already use, 51 on a new one | 51 days |
| Domain age on day one | 30 days + | Whatever yours already is | 0 days |
| What you pay for the mailbox | Reseller rate | Reseller rate | Retail list price |
| Cost of a warmup tool | None | From $97 a month | From $97 a month |
| Domain included | Free | No | No |
| SPF, DKIM and DMARC set up | Before handover | Before handover | You |
Doing it yourself is not cheaper. We buy at reseller rates, so a prewarmed inbox costs about what a provider charges you for the licence alone.
Cost calculator
What does the 51-day wait actually cost you?
Fresh inboxes are cheaper every month. They also send nothing for 51 days. Measure the same money against emails actually sent and the answer flips.
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Cold emails you cannot send while a fresh domain ages and warms
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Fresh: cost per 1,000 emails actually sent in your first 90 days
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Prewarmed: cost per 1,000 emails actually sent in the same 90 days
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Cheaper per email delivered, because nothing is spent waiting
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Orders are placed on Warm Inboxes, run by the same team as this site.
Assumes 15 cold emails per inbox per day and three inboxes to a domain. Fresh carries a $97 a month warming tool, charged as a flat fee for the 51 warming days only — most teams leave it running longer, and tools that charge per mailbox cost more than this at volume. Fresh also buys its own domains at $12; prewarmed includes them and needs no warming tool.
Questions
What does prewarmed actually mean?
Thirty days of aging with the records in place, then twenty-one days of real sending and receiving. A lot of what is sold as prewarmed skips one half, or both.
Are these real Google and Microsoft accounts?
Yes. Proper paid accounts on a domain we age and warm. Not a relay service, and not a seat on somebody else's account.
How fast do I get them?
The same day, on business days. The 51 days of waiting already happened before you ordered.
How many emails a day can I send?
We suggest 15 per inbox per day, with three inboxes on each domain. That is deliberately cautious, and it is the setup that keeps working month after month.
What if a domain stops landing in the inbox?
Ask for the replacement terms in writing before you order, from anyone. Getting a damaged domain back is slow and often does not work, so how fast they replace it is what matters.
Which sending tools do these work with?
Any of them. Smartlead, Instantly, Email Bison, ManyReach and the rest all connect the same way.
Who runs prewarmed.org?
prewarmed.org is operated by the team behind Warm Inboxes (warminboxes.com) and Upscale B2B (upscaleb2b.com). Orders are fulfilled by Warm Inboxes.
Your next campaign can start today.
Get inboxesOrders are placed on Warm Inboxes, run by the same team as this site.