Domain and DNS
A sending domain is registered and SPF, DKIM, DMARC and MX are published before any email goes out.
SPFpass
DKIM 2048pass
DMARCp=quarantine
MXok
Field manual · Chapter 01
What is a pre‑warmed mailbox?
A pre-warmed mailbox is a business email account on Google Workspace or Microsoft 365 that already ran 4-6 weeks of gradual warmup before you get the keys. It arrives with a sending history, so you can start cold outreach at a safe volume on day one instead of waiting a month for a fresh inbox to earn trust.
4 free browser toolsNo signupReviewed November 2026
Cold emails you can send per dayOne mailbox, conservative ramp
Pre-warmedFreshFresh warmup only
Cold emails sent by then, pre-warmed270
Same mailbox, bought fresh0
How a mailbox gets pre-warmed
Four stages happen before handover. If a provider cannot show you each one, you are buying a label, not a history.
Gradual ramp
The mailbox sends and receives a few emails a day, rising slowly from about 2 to 30, with real opens and replies.
Seed test
Test emails go to seed inboxes at Gmail, Outlook and Microsoft 365 to measure where mail lands before handover.
Gmailinbox
Outlookinbox
M365inbox
Yahoopromotions
Keys change hands
You receive logins, admin access, the domain and the warmup log, then connect the mailboxes to your sending tool.
logins.csv3 rows
warmup_log42 days
super adminyou
domainyours
Pre-warmed, fresh or aged?
Three very different things get sold as "ready to send". Only one of them is a mailbox you own with a history you can check.
Pre-warmed Best for speed
New business mailboxes on a dedicated domain that already ran a documented warmup.
- Time to first campaign
- Same day, at a reduced volume
- Ownership
- Domain and admin can be yours (check)
- Typical cost
- About $6-13 per mailbox a month
- Main risk
- Paying for a warmup you cannot verify
Fresh Cheapest
Brand new mailboxes you create and warm yourself or through a warmup tool.
- Time to first campaign
- 3-6 weeks
- Ownership
- Full, from day one
- Typical cost
- About $3-8 per mailbox + warmup tool
- Main risk
- Lost pipeline while you wait
Aged accounts Avoid
Old consumer accounts (often Gmail) resold after years of unrelated use.
- Time to first campaign
- Immediate
- Ownership
- None you can prove
- Typical cost
- Varies
- Main risk
- Breaks provider terms, gets suspended
Full breakdown: pre-warmed vs fresh vs aged mailboxes. Price ranges from public provider pricing checked November 2026.
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Live DNS
SPF, DKIM and DMARC checker
Score any sending domain in seconds and get the exact fix for each failing record.
Check a domain →SPF ........ pass
DKIM ....... google
DMARC ...... p=none
MX ......... google
score 82/100
Planner
Mailbox and domain calculator
Turn a meetings goal or a daily send target into mailboxes, domains and monthly cost.
Size your fleet →goal ....... 20 meetings
sends/day .. 1,000
mailboxes .. 34
domains .... 12
Generator
Warmup schedule builder
Get a day-by-day ramp for new mailboxes, with pause rules, and download it as CSV.
Build a schedule →day 1 ..... 2
day 7 ..... 7
day 14 .... 13
day 28 .... 24
day 42 .... 30
Calculator
Cost of waiting
See how much pipeline a 6-week warmup costs you compared with starting pre-warmed.
Run the numbers →not sent .. 18,900
replies .... 189
meetings ... 38
pipeline ... $57k
The numbers that matter
Four figures every cold email setup is built around.
Cold emails per mailbox~30/dayIndustry working limit
Mailboxes per domain3Spreads reputation risk
Warmup before cold sends4-6 wkFor a fresh mailbox
Gmail spam rate ceiling0.3%Google sender rules
Details and official platform limits: cold email sending limits for Google Workspace and Microsoft 365.
Start here
Questions people ask
What is a pre-warmed mailbox?
A pre-warmed mailbox is a business email account, usually on Google Workspace or Microsoft 365, that has already run 4-6 weeks of gradual warmup activity before it is handed to you. The sending history it built lets you start cold outreach at a conservative volume (about 30 emails per day) right away instead of waiting a month or more.
Is a pre-warmed inbox the same as a pre-warmed email account?
Yes. Pre-warmed mailbox, pre-warmed inbox and pre-warmed email account are three names for the same product. "Pre-warmed domain" is related: it is the sending domain those mailboxes live on, and most of the reputation lives at the domain level.
How long does it take to warm up a new mailbox yourself?
Most teams plan 3-6 weeks. A safe ramp starts at 2-5 warmup emails a day and adds a few per day until it reaches about 30, while authentication and engagement signals stay healthy. Many teams wait 4 weeks before sending any real cold email from a new domain.
How many emails can a pre-warmed mailbox send per day?
Plan around 30 cold emails per mailbox per day, with 3 mailboxes per sending domain. Google Workspace technically allows 2,000 messages per user per day, but that is a platform ceiling, not a safe cold email volume.
Where can I buy pre-warmed mailboxes?
Several providers sell them, including Getlead, Zapmail, InboxKit, Litemail and Instantly. Our recommendation is Getlead because the domain is registered to you, super admin is transferred and the daily warmup log plus seed report come with the logins. The full side-by-side comparison is on prewarmedmailboxes.com.
Does a pre-warmed mailbox guarantee inbox placement?
No. Warmup gives the mailbox and domain a sending history, but placement still depends on your list quality, your copy, your volume and how recipients react. Treat any "100% inbox" promise as a red flag.