Best Email Warmup Tools (2026): 11 Compared by Inbox Cost

This guide compares the best email warmup tools of 2026 by what it costs to warm 1, 5 and 10 inboxes, and what each tool's warmup actually includes.

Disclosure: we make Alien Mail, which is on this list. Every other price comes from the tool's own pricing page.

The short answer: If you already pay for Instantly ($47), Smartlead ($39) or lemlist ($69), use the warmup inside it. It covers all your inboxes at no extra cost. If you need warmup on its own, TrulyInbox and Mailivery are the cheapest at $29 a month, but they share one daily volume across all your inboxes. MailReach ($19.50) and Warmup Inbox ($15) charge per inbox, so they get expensive past 5 inboxes. Alien Mail warms every inbox free and charges only for cold emails sent.

Looking for free plans only? See free email warmup tools.

What it costs to warm 1, 5 and 10 inboxes

The right tool depends on how many inboxes you warm. Per-inbox pricing is cheapest for 1 inbox and most expensive for 10, while bundled and shared-volume plans stay flat.

Monthly billing in USD. Shared plans split one daily volume across all inboxes: 200 a day across 10 inboxes is 20 each. Bundled tools also cap how many cold emails you send: Instantly Growth 5,000 a month, Smartlead Base 6,000, lemlist Email 50,000.

Bundled warmup or a standalone warmup tool?

Pick bundled warmup if you send cold email from a tool that includes it, and a standalone tool if you need warmup beside a sender without warmup. Running two warmup tools on one inbox doubles its daily warmup volume, which looks less natural.

• Bundled (Instantly, Smartlead, lemlist, Alien Mail): one bill and one dashboard, and warmup covers every inbox you connect. You pay the monthly plan even in months you don't send, except on Alien Mail, which has no monthly fee.

• Standalone (TrulyInbox, Mailivery, Warmup Inbox, MailReach, Warmbox, Warmy.io, Mailflow): works with any sender, often with placement tests and more detailed reports. You pay for it on top of your sending tool.

Shared volume vs per-inbox pricing

Shared-volume plans look cheap until you add inboxes, because the same daily volume is split thinner. Per-inbox plans keep each inbox's volume fixed but multiply the price.

A new inbox ramps toward 30 to 40 warmup emails a day, so a shared $29 plan suits up to about 5 inboxes. At 10, move up a tier or switch to per-inbox pricing.

The 11 best email warmup tools in detail

Warmup built into a sending tool

1. Alien Mail: free warmup, pay per email sent

Alien Mail warms every inbox you connect for free, with no inbox limit and no monthly fee. You pay only for cold emails, with prepaid credits from about $1.20 per 1,000 emails at volume, and warmup emails never use credits.

• Best for: teams that want warmup and sending in one tool without a subscription

• Watch out for: newer than most tools on this list, with fewer integrations

2. Smartlead: $39 a month

Smartlead's Base plan ($39 a month) includes its warmup pool and unlimited mailboxes, with 6,000 emails a month and 2,000 contacts. Premium warmup is sold separately.

• Best for: high-volume senders who want unlimited mailboxes on one plan

• Watch out for: agencies pay more for client workspaces, from $29 a month on Pro

3. Instantly: $47 a month

Instantly's Growth plan ($47 a month) includes warmup on every plan, with 5,000 emails a month and 1,000 contacts. Hypergrowth is $97 a month for 125,000 emails.

• Best for: agencies already sending from Instantly

• Watch out for: warmup stops if you cancel the plan

4. lemlist (lemwarm): $69 a month

lemlist's Email plan ($69 a month) includes lemwarm, 50,000 emails a month and unlimited senders and users. The Multichannel plan is $109 per user.

• Best for: teams already on lemlist

• Watch out for: expensive for warmup alone; best if you also send from lemlist

Warmup-only tools

5. TrulyInbox: $29 a month, shared volume

TrulyInbox's Starter plan ($29 a month) covers unlimited inboxes sharing 200 warmup emails a day. Growth ($99) raises that to 1,000 and adds report exports and custom schedules, and Scale ($199) to 3,000. There's a 7-day trial with no card, and a free plan for 1 inbox.

• Best for: the cheapest standalone warmup for up to about 5 inboxes

• Watch out for: the shared limit; 10 inboxes on Starter get 20 a day each

6. Mailivery: $29 a month, shared volume

Mailivery's Starter plan ($29 a month) covers unlimited mailboxes sharing 200 warmup emails a day, at up to 100 per mailbox. It includes 10 inbox placement test credits and 100 verification credits. Professional ($79) shares 800 a day, and Business ($199) 2,500.

• Best for: small teams that want placement tests in the entry plan

• Watch out for: its page lists different yearly limits in two places, so confirm before buying

7. Mailflow: $49 a month for up to 100 addresses

Mailflow's Silver Pool ($49 a month) warms up to 100 addresses at up to 30 a day each. Gold ($99) raises that to 50 a day. QuickMail users get Mailflow warmup inside QuickMail.

• Best for: many inboxes on a flat price

• Watch out for: 30 a day per address is at the low end of a full ramp

8. Warmy.io: from $49 a month

Warmy.io prices plans by warmup volume rather than per inbox, from $49 a month, with a 7-day trial and no card. It also offers free single-use tools: a deliverability test, blacklist checker and SPF checker.

• Best for: teams that want guided setup and lots of free test tools

• Watch out for: per-inbox volume isn't listed, so price 10 inboxes with sales

9. Warmup Inbox: $15 per inbox

Warmup Inbox's Basic plan is $15 per inbox a month for 75 warmup emails a day, with spam and category monitoring and API access. Pro is $49 per inbox for 250 a day, and Max $79 for 1,000.

• Best for: 1 to 3 inboxes that need a steady 75 a day each

• Watch out for: 10 inboxes cost $150 a month

10. MailReach: $19.50 per inbox

MailReach charges $19.50 per mailbox a month for up to 100 warmup emails a day, with at least 20 spam-test credits and domain health checks. Yearly billing saves 20%, and there's no free trial.

• Best for: teams that want warmup and inbox placement tests in one tool

• Watch out for: 10 inboxes cost $195 a month, and its page's bundle totals don't match the per-mailbox rate

11. Warmbox: $19 for 1 inbox

Warmbox's Solo plan is $19 a month for 1 inbox at 50 warmup emails a day. Start-up is $79 for 3 inboxes (250 a day), Growth is $159 for 6 inboxes (500 a day), and larger teams need a custom plan. Lower prices apply with yearly billing.

• Best for: 1 to 6 inboxes with spam-folder removal and spam score monitoring

• Watch out for: about $26 per inbox at 6 inboxes, and custom pricing above that

Deliverability services (not warmup tools)

Folderly costs $96 per mailbox a month on a yearly plan, and its pricing page doesn't mention warmup. Treat it as a deliverability service, not a warmup tool. Its Inbox Insights placement tests start free (2 tests a month) and cost $79 a month for 100.

Head-to-head: the comparisons people search for

Warmup Inbox alternatives: for many inboxes, TrulyInbox or Mailivery ($29 shared). For placement tests, MailReach. Bundled with sending, Instantly, Smartlead or Alien Mail.

Warmbox alternatives: for more than 6 inboxes, Mailflow ($49 for up to 100 addresses) or TrulyInbox. For per-inbox pricing with tests, MailReach.

Email warmup tool vs inbox placement tool

A warmup tool builds your reputation; an inbox placement tool measures where your emails land. You need warmup first. A placement test tells you whether the warmup worked at Gmail, Outlook and Yahoo.

Best email warmup tool for each situation

• You already pay for Instantly, Smartlead or lemlist: use its built-in warmup.

• Warmup and sending with no monthly fee: Alien Mail.

• Cheapest standalone warmup, up to 5 inboxes: TrulyInbox or Mailivery at $29.

• Many inboxes on a flat price: Mailflow at $49 for up to 100 addresses.

• Warmup plus placement tests: MailReach.

• 1 to 3 inboxes with steady volume: Warmup Inbox at $15 each.

• Free plans only: see free email warmup tools.

How we compared

We opened each tool's pricing page on 2 Nov 2026 and priced the cheapest plan that covers 1, 5 and 10 inboxes, using monthly billing. Where a plan shares one daily volume across inboxes, we show the volume each inbox gets. A feature missing from a pricing page is marked "not stated", not "missing". We make Alien Mail and list it first in each group. We didn't run our own deliverability tests on these tools.

Frequently asked questions

What is the best email warmup tool? It depends on how many inboxes you warm and what you send from. If your cold email tool includes warmup, use it. For warmup on its own, TrulyInbox and Mailivery are cheapest up to about 5 inboxes; MailReach adds placement tests at $19.50 per inbox.

What's the cheapest email warmup tool for 10 inboxes? Alien Mail warms 10 inboxes free. Among paid warmup-only tools, TrulyInbox and Mailivery cost $29 a month, but each inbox gets only 20 warmup emails a day; Mailflow covers up to 100 addresses at 30 a day for $49.

Do I need a warmup tool if my cold email tool has warmup? Usually not. Instantly, Smartlead, lemlist and Alien Mail warm every connected inbox. A second warmup tool on the same inbox doubles its warmup volume.

Is per-inbox or shared-volume pricing better? Shared volume is cheaper for a few inboxes; per-inbox pricing keeps each inbox's volume fixed as you add more. Past 5 inboxes on a $29 shared plan, each inbox drops below 40 a day.

What's the difference between email warmup and an inbox placement test? Warmup builds reputation by exchanging emails with real inboxes every day. A placement test checks where one email lands at each provider. Use warmup daily and placement tests before campaigns.

How many warmup emails a day does an inbox need? A new inbox ramps up toward 30 to 40 warmup emails a day over 3 to 4 weeks. Keep warmup running after campaigns start.

Can a warmup tool fix a blacklisted domain? Rarely. Get delisted and fix the cause first; see our blacklist removal guide.

Key terms

• Email warmup: sending a small, rising number of emails that get opened and replied to, so an inbox earns trust.

• Shared volume: one daily warmup limit split across all connected inboxes.

• Per-inbox pricing: a price for each inbox, with its own daily warmup limit.

• Inbox placement test: a test email sent to seed inboxes to see whether it lands in the inbox, promotions or spam.

• Bundled warmup: warmup included in a cold email sending tool's plan.

Related reading

• Free email warmup tools: what's actually free

• What is email warmup?

• Email warmup schedule

• Alien Mail vs MailReach · Alien Mail vs Warmy.io

Start free email warmup → · See Alien Mail pricing