Email warmup tools · you may already have one
If you send cold email from Instantly or Smartlead, you already have warmup. Warmup means sending small, safe emails so a new inbox looks normal before cold volume.
our pick for you
Our pick
If you send cold email from Instantly or Smartlead, you already have warmup. Pick Instantly if you want warmup, sending and replies in one place for $47 a month. Buy a separate warmup tool only for an inbox you never send campaigns from.
- Instantly Growth is $47 a month and includes unlimited email accounts and warmup.
- Smartlead includes a warmup pool on every plan, from Base at $39. A warmup pool is the group of inboxes that trade safe emails with yours.
- A standalone warmup tool like Warmup Inbox charges per inbox. Basic is $19 per inbox a month, or $15 billed yearly.
- At 20 inboxes, Warmup Inbox Basic costs $255 a month, or $195 a month billed yearly.
- A green warmup score does not prove your campaign lands in the inbox. Test real sends with seed inboxes, which are a few inboxes you own and check by hand.
- Pre-warmed inboxes, which the seller has already warmed for you, cost about twice as much as fresh ones and save you about 3 weeks.
Ranked picks
- #1
Instantlytop pickBest for: New senders who want warmup, sending and replies in one tool.
- Warmup is included on every inbox you connect, at no extra cost.
- Growth includes advanced warmup options.
- You can buy pre-warmed Google accounts inside Instantly for $10 a month each. Pre-warmed means Instantly has already warmed them, so you can send sooner.
- #2
Best for: Agencies and teams that keep every lead and want a better warmup pool as they grow.
- Warmup is included on every plan.
- The warmup pool gets better on higher plans, so you know what you are paying for.
- Pre-warmed Google inboxes are $9 a month plus $18 a year per domain.
- #3
Best for: Teams that need fresh Google inboxes to warm up inside their sender.
- The math: 20 inboxes cost 20 × $3.50 = $70 a month.
- Each inbox has a stated daily limit, so you can plan your volume.
- #4
Best for: A founder's main inbox or a CRM sender that never runs through a sequencer.
- It warms an inbox you send from by hand, outside any cold email tool.
Compare
| Tool | Price band | Best for | Dealbreaker |
|---|---|---|---|
| #1 Instantly | Growth is about $47 a month. | New senders who want warmup, sending and replies in one tool. | Growth holds up to 1,000 uploaded contacts. |
| #2 Smartlead | Base is $39 a month. | Agencies and teams that keep every lead and want a better warmup pool as they grow. | Base gets the lowest warmup pool. |
| #3 ScaledMail | Google is $3.50 a mailbox. | Teams that need fresh Google inboxes to warm up inside their sender. | Scaledmail inboxes still need warmup before cold volume. |
| #4 Warmup Inbox | From $15 an inbox yearly. | A founder's main inbox or a CRM sender that never runs through a sequencer. | You pay per inbox. |
MethodHow we scored these tools▾
Each tool is priced for the same 20 Google inboxes, using its own published prices on October 13, 2026. Warmup tools that charge per inbox are set beside senders that include warmup in the plan.
Who it's for
buy if
- Use this page if you are setting up new inboxes for cold email.
- Use this page if you pay for a warmup tool and also pay for a sender like Instantly or Smartlead.
skip if
- Skip this page if you want a full guide to getting into the inbox. This page only covers warmup tools.
- Skip this page if you only send newsletters to people who signed up.
The short answer
If you send cold email from Instantly or Smartlead, you already pay for warmup. Pick Instantly if you want warmup, sending and replies in one place for $47 a month. Pick Smartlead if you keep every lead or run email for clients. Buy a separate warmup tool only for an inbox you never send campaigns from.
What warmup does for a new inbox
Warmup means sending small, safe emails between friendly inboxes, so Google and Microsoft learn to trust a new address.
Inbox placement is where your email lands: the inbox, or spam. Warmup helps placement, but it does not measure it.
A seed test is a real send to a few inboxes you own, so you can see where it lands.
What warmup costs for 20 inboxes
Take a team with 20 Google inboxes, sending about 500 cold emails a day. Prices are from October 13, 2026.
The math for volume: 500 × 30 days = 15,000 emails a month. That is more than Instantly Growth's 5,000 or Smartlead Base's 6,000, so this team needs a bigger plan. Instantly Hypergrowth at $97 or Smartlead Pro at $94, which sends up to 90,000 a month, both cover it.
The math for inboxes: Scaledmail is 20 × $3.50 = $70 a month. Inboxkit is 20 × $3 = $60 a month.
Warmup inside the sender costs nothing extra. Hypergrowth and Pro both warm all 20 inboxes.
A separate tool costs real money. Warmup Inbox Basic for 20 inboxes is $255 a month, or $195 billed yearly. The math: $195 × 12 = $2,340 a year for a job your sender already does.
The math to skip warmup: Instantly pre-warmed Google accounts are $10 × 20 = $200 a month. Smartlead's pre-warmed inboxes are $9 × 20 = $180 a month, plus $18 a year per domain.
When to pay more for pre-warmed inboxes
A pre-warmed inbox is one the seller has already warmed for you, so you can send sooner.
The math: Instantly charges $10 a month for a pre-warmed Google account and $5 for a fresh one. That is 2 times the price. Smartlead charges $9 for pre-warmed and $4.50 for fresh.
Pay the extra only when your campaign date is fixed and you can't wait about 3 weeks.
How to check that warmup worked
Warmup tools show a score. One tool reviewer on X saw green warmup for weeks while a seed test showed the campaign missing the inbox.
Before a real campaign, mail a few inboxes you control on Gmail, Outlook and a private domain. Trust where those land.
How early to buy your inboxes
An outbound seller on X, @ZaidAD_, wrote on May 30, 2026 that you should buy domains and inboxes at least 3 weeks before you plan to send. No provider publishes a fixed rule.
What users say
“The warmup score is not a placement score.”
“Buy domains and inboxes at least 3 weeks before u plan to”
Common questions
Is there a free email warmup tool?▾
Warmup is included in every paid Instantly and Smartlead plan, and in Instantly's 14-day trial, which needs no card.
How long should I warm up a new inbox?▾
@ZaidAD_ on X wrote on May 30, 2026 to buy inboxes at least 3 weeks before you send. No provider publishes a fixed rule.
Do I need warmup if I buy pre-warmed inboxes?▾
You can start sending sooner. Keep warmup running in your sender after you start, since it is included at no extra cost.
Is a warmup score the same as inbox placement?▾
No. A warmup score shows how the warmup emails did. Run a seed test to see where your real campaign lands.
what to do next
What to do next
Count your inboxes, then check if your sender already warms them. If you are starting out, use Instantly Growth at $47 and connect your inboxes. Start the 14-day trial first. If you keep every lead or run email for clients, use Smartlead. If you need fresh inboxes, get them from Scaledmail, Inboxkit, Zapmail or Premium Inboxes. Try Instantly Try Smartlead Next · Inbox providers compares where to buy inboxes · Smartlead vs Instantly helps you pick a sender.