Best Email Warmup Tools (2026): Top Picks By Sending Setup

Choose your email warmup tool by how many mailboxes you run, and treat vendor network-size claims as unmeasured. TrulyInbox suits many mailboxes on a budget. Instantly and Lemwarm suit teams already sending from those platforms. MailReach and Warmforge suit a handful of mailboxes where you want placement testing alongside warmup.

That rule holds because warmup cost scales with mailbox count on some tools and not on others. MailReach and Warmforge charge per mailbox, while TrulyInbox, Instantly and Lemwarm price the plan.

Prices and plan limits here come from vendor pages that change and contradict themselves in places, so confirm the figure on the vendor's own pricing page before you pay. No warmup tool replaces correct DNS setup or sensible sending volume.

Email Warmup Tools At A Glance

The five tools fall into three groups. Many mailboxes on a budget, an existing sequencer that bundles warmup, and a few mailboxes where you want testing next to warmup.

Prices are the figures shown on each vendor's pricing page.

1. TrulyInbox: Best For Many Mailboxes On A Budget

TrulyInbox is a standalone warmup tool. You connect your sending mailboxes, pick a plan, and the plan sets how many warm-up emails go out per day. The pricing model is the draw, because paid plans do not charge per mailbox.

It is built for the team that runs a lot of mailboxes and wants a flat bill. If you spread cold volume across dozens of addresses, a per-mailbox price punishes you, and TrulyInbox does not.

Those figures are from TrulyInbox's pricing page, and the Starter plan at $22 per month on annual billing is the cheapest way in to unlimited mailboxes among the five tools here.

Strengths:

• Flat pricing: Unlimited mailboxes on every paid plan means the bill does not grow when you add an address.
• A real free plan: The Free plan lets you test one mailbox before you commit anything.
• Clear tiers: The daily warm-up cap steps up from 200 to 1,000 to 3,000, so you can see what each upgrade buys.

Trade-offs:

• Caps rise with the tier: The daily warm-up email cap is what you pay more for, not the mailbox count.
• Free plan is thin: The Free plan has no API access and only 10 warm-up emails per day.
• Annual discount: The lowest prices need annual billing, and monthly billing costs $7 to $30 more depending on the plan.

Key capabilities:

• Unlimited mailboxes on Starter, Growth and Scale
• A daily warm-up email cap from 10 up to 3,000 per day
• A free plan with one account
• Annual and monthly billing

Good fit:

• Agencies and outbound teams running many sending addresses
• Anyone who wants to test warmup on one mailbox for free first

Not a fit:

• Teams that need API access on the free tier
• Buyers who want the pricing page to spell out per-mailbox caps

The limitation that matters most is the cap. TrulyInbox's page does not say whether the daily warm-up cap is per mailbox or pooled across all of them. If it is pooled, 200 emails a day on Starter spread over 50 mailboxes is 4 per mailbox. Check that before you connect dozens of mailboxes.

2. Instantly: Best For Teams Already Sending From Instantly

Instantly is a cold email platform with warmup built into the plan. You do not buy warmup as a separate product. You buy the sequencer, and warmup comes with it.

That makes it the obvious pick when Instantly is already where your campaigns run, or about to be. The question is less "which warmup tool" and more "do I want Instantly as my sender."

Instantly's pricing page shows warmup and unlimited accounts included on the Growth plan at $47 per month. The Light Speed plan is left out of the table because the page does not state whether warmup is included.

Strengths:

• Warmup is bundled: You pay for the sequencer and warmup rides along, with no second invoice.
• Unlimited accounts: Growth and Hypergrowth both list unlimited email accounts, so adding a mailbox does not change the price.
• Low entry price: At $47 per month, Growth is the cheapest route here to warmup plus a sequencer.

Trade-offs:

• No stated warm-up volume: The vendor publishes no per-day warm-up volume.
• No stated warm-up trial: The vendor states no free warm-up trial.
• Vendor claims: Instantly's warm-up network size and reply claims on its email warmup page are the vendor's own and unmeasured.

Key capabilities:

• Unlimited email warmup on Growth and Hypergrowth
• Unlimited email accounts on both plans
• Warmup inside the same product that sends the campaigns

Good fit:

• Teams already running sequences in Instantly
• Buyers who want one product for sending and warmup

Not a fit:

• Teams who send from another platform and only want warmup
• Buyers who need a published daily warm-up volume

The limitation to weigh is what the page leaves out. There is no daily warm-up volume and no free warm-up trial, so you are trusting the product without being able to size it first.

3. Lemwarm: Best For Lemlist Users

Lemwarm is lemlist's warmup feature. It is included in every lemlist plan, so you do not choose Lemwarm on its own. You choose lemlist as your sequencer and Lemwarm comes with it.

The useful question is whether you want lemlist for outreach. If you do, warmup is covered. If you do not, there is nothing to buy here, because a standalone Lemwarm price is not published.

According to lemlist's pricing page, Lemwarm is included in all lemlist plans, and the Email plan is $55 per month on yearly billing. The same page shows a 14-day trial with Multichannel features and 200 free credits.

Strengths:

• Included on every plan: Warmup does not depend on which lemlist tier you buy.
• Unlimited senders: The Email plan lists unlimited users and email senders.
• A trial: The 14-day trial lets you try the product before paying.

Trade-offs:

• No standalone price: You cannot buy Lemwarm without lemlist.
• Yearly pricing: The $55 and $87 figures are yearly-billing rates.
• Custom top tier: Enterprise pricing is not published.

Key capabilities:

• Warm-up included in all lemlist plans
• A deliverability hub on the Email plan
• Unlimited users and email senders on the Email plan
• A 14-day trial with 200 free credits

Good fit:

• Teams who already use lemlist or plan to
• Buyers who want warmup folded into a sequencer bill

Not a fit:

• Anyone who wants warmup for mailboxes that send from another platform
• Buyers who need a published warm-up mailbox minimum

The limitation that matters is the missing standalone price. A warm-up mailbox minimum is not published either, so lemlist is a decision about the whole sequencer, not about one feature.

4. MailReach: Best For A Few Mailboxes With Spam Testing

MailReach prices per mailbox. Its All-In-One plan pairs the warmer with a spam tester, so you can warm a mailbox and test where its messages land in the same product.

That pairing is the reason to pick it. If you run a handful of mailboxes and want to see placement results next to warmup, you pay a simple per-mailbox price and get both.

MailReach's pricing page shows the All-In-One plan at $19.50 per mailbox per month on monthly billing. The annual option is labelled Save 20% with no rate shown, so this guide does not quote one. The 20% off the first 30 days on the first mailbox is a discount, not a trial.

Strengths:

• Simple pricing: One price per mailbox, so the bill is easy to predict.
• Testing included: The spam tester sits in the same plan as the warmer.
• Pay-as-you-go credits: Spam tester credits are available without a subscription to the warmer.

Trade-offs:

• Linear cost: Every extra mailbox adds another $19.50 a month.
• Annual rate hidden: The page shows Save 20% but not the resulting price.
• Discount, not a trial: The first-month offer still means paying.

Key capabilities:

• A warmer and a spam tester in one plan
• Per-mailbox monthly billing
• Pay-as-you-go spam tester credits
• A 20% discount on the first 30 days for the first mailbox

Good fit:

• Teams with a few mailboxes who want spam testing next to warmup
• Buyers who prefer a price they can multiply in their head

Not a fit:

• Teams running dozens of mailboxes on a tight budget
• Buyers who want a free trial

The limitation is cost growth. Because the price is per mailbox, the bill climbs in a straight line, and the cost section below shows where that stops making sense.

5. Warmforge: Best For Paying Per Mailbox Slot

Warmforge charges per warm-up slot, billed quarterly, and sells placement tests as separate plans. A slot is one mailbox in warmup.

You buy slots for the mailboxes you warm, and add a placement-test plan only if you want testing. That split keeps the entry price low for a small setup.

Warmforge's pricing page shows an Email Warm Up slot at $10 per month billed quarterly, with 1 free warm-up slot and 1 free inbox placement test each month.

Strengths:

• Lowest slot price: At $10 per slot, Warmforge is cheaper per mailbox than MailReach's $19.50.
• A free allowance: One free slot and one free placement test a month, every month.
• Testing is optional: You add a placement-test plan only if you want one.

Trade-offs:

• No free trial: The page states there is no free trial beyond the free allowance.
• No published slot maximum: The page does not say how many slots you can buy.
• No monthly-billed slot price: The $10 figure is on quarterly billing.

Key capabilities:

• Per-slot warm-up pricing
• Placement tests as separate plans
• 100 tests across 50 mailboxes on Placement Tests Pro
• Unlimited tests across 250 mailboxes on Placement Tests Growth

Good fit:

• Small setups that want cheap warmup and may add testing later
• Buyers who want to try one slot for free

Not a fit:

• Teams who need a monthly-billed slot price on the page
• Teams warming dozens of mailboxes, where per-slot costs add up

The limitation that matters is the missing ceiling and monthly price. With no published slot maximum, a large mailbox count means asking before you plan around it.

What An Email Warmup Tool Does

An email warmup tool sends and answers automated messages between a connected mailbox and a network of other mailboxes, so a new sending address builds a history of normal activity before cold campaigns begin. The tool exists to establish sending reputation gradually.

Warmup has limits. It does not fix a bad list, missing or wrong authentication records, or aggressive cold volume. A warmed mailbox that blasts an unverified list will still land in spam.

The practical effect is that warmup is a head start, not a licence. It gives a new address a record of ordinary back-and-forth before it starts sending to strangers. What you do after that record exists still decides where your mail lands.

How We Chose These Email Warmup Tools

Every price and limit in this guide comes from the vendor's own pricing page. No tool was run through a controlled placement test for this article, so nothing here claims one tool lands more mail in the inbox than another. Tools whose pricing pages the research could not read were left out.

The five tools were compared on the same criteria.

• Connectable mailboxes: How many mailboxes a plan allows, taken from the pricing page.
• Daily warm-up capacity: The warm-up emails per day a plan states, or a note that none is published.
• Pricing model: Whether the vendor charges per mailbox or per plan, and the billing basis.
• Free option: Whether the vendor offers a free plan, a free allowance or a trial.
• Built-in or standalone: Whether warmup is a product on its own or part of a sequencer.

Roundup pages like this one also feed AI answers about which tool to pick, which is why Generative Engine Optimization matters to vendors in this category. Being the page an engine cites is the job of answer engine optimization.

How To Pick An Email Warmup Tool By Sending Setup

The rule is simple. Look at how many mailboxes you run and whether a sequencer already does your sending. The main switch is pricing model. Per-mailbox tools get expensive as you add addresses, and plan-priced tools do not.

• Many mailboxes on a budget: If you spread cold volume across a lot of addresses, pick TrulyInbox, because its paid plans allow unlimited mailboxes at a flat price. It does not suit you if you need the pricing page to spell out a per-mailbox cap, since TrulyInbox's page does not say whether the daily cap is per mailbox or pooled.
• Already on a sequencer: If you already send from a sequencer that bundles warmup, pick Instantly or Lemwarm, because warmup is included in the plan and a separate tool adds a second bill. It does not suit you if your campaigns run on a different platform, since neither bundle can be bought for warmup alone.
• A few mailboxes with testing: If you run a few mailboxes and want testing next to warmup, pick MailReach or Warmforge, because both price per mailbox and both sell placement or spam testing. It does not suit you once the mailbox count climbs, because the bill rises in a straight line with every address you add.

The per-mailbox versus per-plan split is the main switch. A per-mailbox tool is cheap at one address and expensive at fifty. A plan-priced tool is the reverse, because the price is the same whether you connect three mailboxes or thirty, and the limit moves to the daily cap or to the sequencer you have to buy with it. Decide which of those two limits you would rather live with before you compare anything else.

If two groups both fit, start with what you already pay for. A team on Instantly or lemlist has warmup in hand, so the only question is whether the bundled version is enough. A team on a different sender should compare TrulyInbox against the per-mailbox pair at its real mailbox count, using the cost table below.

Daily volume matters too. Smartlead's benchmark of its own senders puts the median cold sender at 14 emails per mailbox per day, so small per-mailbox volumes do not need the biggest warmup tier. If you are choosing a sequencer-bundled option, you are comparing outbound prospecting tools as much as warmup. Teams running many mailboxes also need list volume, which the guide to bulk email finder tools covers.

What Email Warmup Costs At 1, 10 And 50 Mailboxes

Per-mailbox tools multiply. A Warmforge slot at $10 per month gives $10 for 1 mailbox, $100 for 10 ($10 x 10) and $500 for 50 ($10 x 50). MailReach at $19.50 per mailbox gives $19.50, $195 ($19.50 x 10) and $975 ($19.50 x 50). Plan-priced tools stay flat on mailbox count, but each carries its own daily cap or a bundled sequencer.

The break-even sits at a few mailboxes. Two MailReach mailboxes cost $39 per month, already more than TrulyInbox Starter at $22. Three Warmforge slots cost $30, also past $22. Five Warmforge slots cost $50, which passes Instantly Growth at $47.

Flat does not mean free of limits. Each flat price carries a catch, and the catch is different for each tool.

• TrulyInbox Starter: The $22 per month covers unlimited mailboxes but caps warm-up at 200 emails per day. If that cap is pooled, 50 mailboxes share 200 emails, which is 4 each. The Growth plan lifts the cap to 1,000 per day at $84 per month on annual billing.
• Instantly Growth: The $47 per month covers unlimited accounts and unlimited warmup, but it is the price of the sequencer. You only get a good deal if Instantly is where you send.
• Lemwarm: The $55 per month on the lemlist Email plan is the price of the whole sequencer on yearly billing. Warmup is the part you do not pay extra for, so the comparison is lemlist against your current sender.

The cap or the bundle is the thing to check before you trust a flat price at 50 mailboxes.

All prices are in US dollars as the vendor pages show them. Billing basis differs by tool, with quarterly, monthly and yearly options, so the monthly figures above are not all the same kind of commitment.

How Long To Warm Up Before Cold Sending

Two sources give two answers, and they measure different things. SyncGTM advises about 2 to 3 weeks of warmup for a new mailbox on an aged domain and 4 to 6 weeks for a new domain before cold outreach at meaningful volume.

Smartlead's benchmark of its own senders reports an average of 8 days of warmup before a first campaign, down from 9.4 days a year earlier. That is a count of what senders actually do. The SyncGTM range is what is advised.

• New mailbox on an aged domain: About 2 to 3 weeks of warmup.
• New domain: About 4 to 6 weeks of warmup.
• What senders do in practice: An average of 8 days before a first campaign.

Read the three lines as scenarios, not promises. If you are adding one mailbox to a domain that already sends mail, plan for the 2 to 3 week end of the range before you send cold at volume. If you bought a fresh domain, plan for the 4 to 6 week end, because a new domain has no history at all. The 8-day figure is an average of what Smartlead's own senders do, not a safe minimum.

During the wait, keep the mailbox connected to the warmup tool and do not send campaigns from it. Check authentication records, confirm the sending domain resolves, and decide your starting daily volume so day one of cold sending is a plan rather than a guess.

Use the wait to build the lead list. The guide to email finder tools for sales teams covers where to start.

Is A Warmup Tool Enough On Its Own?

No. Warmup builds sending history, but list quality, authentication records and sending volume decide whether that history holds. A warmed mailbox that sends to a bad list, with broken DNS records or at aggressive volume, will still hurt your deliverability.

Name the three things warmup does not fix, and what to do about each.

• A bad list: Bounces and complaints from contacts who never asked for your mail undo the history warmup built. Verify addresses before the first send.
• Missing or wrong authentication records: Warm-up messages cannot make up for DNS records that are absent or misconfigured. Fix the records first, then warm.
• Aggressive cold volume: A warmed mailbox that jumps to heavy daily sending looks like a new spammer. Ramp volume in steps, and keep per-mailbox volume modest.

The dedicated network versus built-in question is about what you already pay for. A standalone warmup tool is a product you buy for warmup alone. A sequencer's built-in warmup arrives inside the sending platform. If you already pay for Instantly or lemlist, the bundled warmup is covered. If you send from somewhere else, you need a dedicated tool.

Warmup is one layer of a bigger stack. Our guide to email deliverability tools covers the rest. Growth Tribune keeps a comparison of email deliverability tools if you want the full field beyond warmup.

Common Email Warmup Mistakes

1. Sending cold volume on day one. A new mailbox has no history, so a burst of cold mail looks like spam from an unknown sender and can damage the address before it has a chance. Start with warmup and ramp volume slowly.
2. Warming a mailbox while sending an unverified list. Bounces undo the work and the warmup subscription is wasted, so run the list through email verification tools and source contacts from B2B email finder tools you trust.
3. Ignoring placement results. Warmup running does not mean mail is landing in the inbox, and a mailbox can sit in spam while the dashboard looks fine. Test placement and act on the result.
4. Connecting many mailboxes without checking the daily cap. A plan with a pooled cap can leave each mailbox with almost no warm-up volume, so the mailboxes stay cold while you pay for them. Confirm how the cap works before you connect them, and ask the vendor if the page does not say.
5. Switching warmup off the day campaigns start. The vendor pages do not say what happens to a mailbox when warmup stops, so ask the vendor before you switch it off on a live mailbox.

Free Email Warmup Tools

Two of the five tools have a free option on the vendor's page.

• TrulyInbox Free: TrulyInbox's pricing page shows a free plan with 1 account, 10 warm-up emails per day and no API access.
• Warmforge free allowance: Warmforge's pricing page shows 1 free warm-up slot and 1 free inbox placement test per month.

A free tier is good for testing one mailbox and seeing how the product behaves. It is not a plan for a full team, because the limits are set for a single address.

Use a free tier for one job. Connect the mailbox you care least about, watch how the product reports activity, and decide whether the paid version is worth it. Do not build a multi-mailbox outbound programme on 10 warm-up emails per day or on one free slot.

How To Tell If Warmup Is Working

Watch inbox placement against spam placement, whether messages get rescued from the spam folder, and the bounce and complaint trend over time. Inbox placement is the share of test messages that reach the inbox.

Two of the five tools sell testing. MailReach's All-In-One plan includes a spam tester, with extra credits pay as you go. Warmforge sells placement tests as separate plans, with Placement Tests Pro covering 100 tests and Placement Tests Growth covering unlimited tests, plus one free test a month.

Pair that with a spam score check. Our guide to free email spam checkers covers the options. A clean score does not prove inbox placement, so treat it as one signal among several.