Instantly warmupfrom $47/moWarmup Inboxfrom $19/moTrulyInboxfree, then $29/moMailReach$25/mailbox
Key takeaways
An email warm up tool sends and answers small volumes of email from a new mailbox so inbox providers learn to trust it before your cold campaigns start. Here is how the seven main options compare.
Instantly includes unlimited warmup for unlimited email accounts on every plan, from $47 a month, so most Instantly users never need another tool.
Smartlead also bundles unlimited warmup from $39 a month, and the quality of its warmup pool goes up with each plan.
Warmup Inbox is the cheapest standalone start at $19 per inbox a month, with 75 warmup emails a day on Basic.
TrulyInbox has the only free forever plan here (1 account, 10 emails a day) and prices by daily volume, not by mailbox.
Lemwarm is free inside every lemlist plan, or $29 per mailbox a month on its own.
MailReach charges $25 per mailbox and adds spam tests, with a free test you can run 3 times a day.
Warmy bundles placement tests, a seed list and DMARC tools, from $49 a month, but doesn't publish its full price list.
Summary
The 7 best email warmup tools at a glance
#
Tool
Best for
Starting price
Free option
Billed by
Network (vendor figure)
1
Instantly
Teams already sending with Instantly
$47 / month, sender included
14-day trial, no card
Plan, unlimited accounts
Over 1,000,000 accounts
2
Smartlead
Agencies on Smartlead
$39 / month, sender included
Trial, no card
Plan, unlimited accounts
Not published
3
Warmup Inbox
A cheap standalone start
$19 per inbox / month
7-day trial, no card
Inbox
30,000+ inboxes
4
TrulyInbox
Many mailboxes on one budget
Free, then $29 / month
Free plan, 1 account
Daily warmup volume
50,000+ inboxes
5
Lemwarm
Lemlist users
$29 per mailbox / month
Included with lemlist
Mailbox
20,000+ domains
6
MailReach
Warmup plus spam testing
$25 per mailbox / month
No trial found
Mailbox
30,000 inboxes
7
Warmy
A full deliverability suite
From $49 / month
7-day trial, no card
Volume
1M+ mailboxes
Monthly-billing prices from each vendor's pricing page. Network sizes are the vendors' own figures and are not independently audited.
Method
How we picked
Vendor pricing
Every price comes from the vendor's own pricing page, monthly billing unless the card says otherwise.
Cost per mailbox
Whether you pay per inbox, per daily volume or nothing extra because warmup ships with your sequencer.
Warmup controls
Ramp-up, daily limits, open and reply rates, and whether the tool pauses itself when bounces spike.
Testing and monitoring
Placement tests, blacklist checks and SPF, DKIM and DMARC checks, and which plan they sit on.
Free option
Free plans, trial length and whether you need a card, so you can test before you commit.
1Instantly warmup, best for teams already sending with Instantly
Best for
Anyone who sends cold email from Instantly or is about to
Instantly email warmup page
Instantly doesn't sell warmup on its own. It comes with the sender, and every plan includes unlimited email accounts and unlimited warmup. Growth is $47 a month, Hypergrowth $107 and Light Speed $358, so adding a tenth or a fiftieth mailbox doesn't change the bill.
The warmup itself ramps slowly, starting at 2 emails on day 1 and 4 on day 2, and emulates opens and reads. You can set open and reply rates and keep warmup to weekdays. Instantly's warmup page says the network has over 1,000,000 real email accounts. Instantly's own advice is 2 to 4 weeks of warmup, ideally 30 days, before a new mailbox sends cold email.
Strengths
Unlimited accounts and warmup on every plan
Configurable open and reply rates
14-day trial with no card
Weaknesses
No warmup-only plan
Not worth it unless you also send from Instantly
Network size differs between Instantly's own pages
Agencies running many client mailboxes inside Smartlead
Smartlead warmup page
Smartlead bundles warmup the same way: unlimited email accounts and unlimited warmup on every plan, from $39 a month on Base ($32 billed yearly). The difference is the pool. Base warms with the Foundation pool, Pro ($94) with Growth, and the two Unlimited plans ($174 and $379) with Premium.
Each mailbox gets its own ramp, and warmup pauses on its own when bounces or spam reports spike. It works with Gmail, Outlook and SMTP mailboxes. Smartlead doesn't publish a pool size, only that it is private and vetted.
The gap is testing. Inbox placement tests live in SmartDelivery, a separate add-on from $49 a month. Our Instantly vs Smartlead comparison goes through both senders plan by plan.
Strengths
Unlimited warmup from $39
Auto-pause on bounce or spam spikes
Gmail, Outlook and SMTP
Weaknesses
Best warmup pool only on the $174+ plans
Placement tests cost extra
No published network size
Pricing
Base $39, Pro $94, Unlimited Smart $174, Unlimited Prime $379 a month. About 17% less billed yearly.
A few mailboxes on a sender that has no warmup of its own
Warmup Inbox homepage
Warmup Inbox is a dedicated warmup tool priced per inbox. Basic is $19 a month ($15 billed yearly) for 75 warmup emails a day, Pro is $59 for 250 a day, and Max is $99 for 1,000 a day. Annual billing saves 20%.
Warmup Inbox says its network has 30,000+ real inboxes and sends 6 million warmup emails a day. Blacklist, SPF and DKIM checks and an inbox placement test are included, and there is an API. Pro adds warmup in specific languages and for specific email providers.
Strengths
$19 entry price
Placement test and authentication checks
7-day trial, no card
Weaknesses
Priced per inbox, so cost grows with every mailbox
75 warmup emails a day on Basic
Language and provider targeting only on Pro
Pricing
Basic $19, Pro $59, Max $99 per inbox a month. 20% off yearly.
4TrulyInbox, best for many mailboxes on one budget
Best for
Teams with lots of mailboxes and modest per-mailbox volume
TrulyInbox homepage
TrulyInbox flips the pricing model. You connect unlimited email accounts and pay for daily warmup volume instead. Starter is $29 a month ($22 yearly) for 200 warmup emails a day, Growth is $99 for 1,000, and Scale is $199 for 3,000. Scale Plus starts at $479.
It is also the only tool here with a free forever plan: 1 account and 10 warmup emails a day, no card. Paid plans add blacklist monitoring and an API, and come with a 7-day trial and a 14-day money-back guarantee. TrulyInbox suggests 2 warmup emails for every cold email you send.
Watch the volume split. The daily allowance is shared across all your accounts, so 200 a day across 20 mailboxes is 10 each.
Strengths
Free forever plan
Unlimited accounts on paid plans
14-day money-back guarantee
Weaknesses
Daily volume is shared across mailboxes
Free plan covers one account
Network size only stated in its partner docs
Pricing
Free, Starter $29, Growth $99, Scale $199, Scale Plus from $479 a month.
Lemwarm is lemlist's warmup tool, and it is included in every lemlist plan. Lemlist's Email plan is $69 a month ($55 yearly) with a 14-day trial, so if you send from lemlist there's nothing extra to buy.
On its own, lemwarm costs $29 per mailbox a month on Essential ($24 yearly) or $49 on Smart ($40 yearly). Lemwarm says its network covers 20,000+ real domains in 100+ countries. It connects Gmail and Outlook in one click and gives each mailbox a deliverability score with a setup check. Lemlist recommends about four weeks of warmup, then two more before full campaigns.
Strengths
Free with every lemlist plan
Deliverability score per mailbox
Quarterly and yearly discounts
Weaknesses
$29 per mailbox standalone adds up fast
No standalone trial found
Over 10 users is custom pricing
Pricing
Essential $29, Smart $49 per mailbox a month. Included in lemlist from $69.
6MailReach, best for warmup plus spam testing
Best for
Senders who want to test placement as often as they warm
MailReach homepage
MailReach is $25 per mailbox a month for 1 to 5 mailboxes, dropping to $19.50 from the sixth. Each mailbox sends up to 100 warmup emails a day and comes with 20 spam test credits. MailReach says its network is 30,000 real inboxes on business Google Workspace and Microsoft 365 accounts.
The testing side is the draw. A free spam test runs up to 3 times a day without an account, and paid mailboxes add blacklist, SPF, DKIM and DMARC checks and a REST API. MailReach recommends at least 14 days of warmup.
Strengths
Spam test credits with every mailbox
Free spam test, 3 a day
Volume discount from 6 mailboxes
Weaknesses
No free trial found
Per-mailbox price adds up for agencies
100 warmup emails a day cap
Pricing
$25 per mailbox a month for 1 to 5, $19.50 from 6.
Teams that want warmup, testing and DMARC in one tool
Warmy homepage
Warmy packs more than warmup into each plan: inbox placement credits, a 500K+ US seed list, email verification, DMARC tools, blacklist alerts and Google Postmaster data. Warmy says its network has 1M+ mailboxes and warms in 30+ languages.
Pricing is the weak spot. Warmy publishes only a starting price of $49 a month, set by volume, and its own pages tell you to confirm placement credit allowances with the team. The 7-day trial needs no card, so test it on one mailbox first.
Often you don't. Instantly and Smartlead both include unlimited warmup for every connected mailbox, and lemlist includes lemwarm. Paying $19 to $25 per mailbox on top of that warms the same inbox twice.
A standalone tool makes sense in three cases: your sender has no warmup of its own, you send from a regular Gmail or Outlook account outside a sequencer, or you want placement tests and blacklist alerts that your sender doesn't offer. Before you choose a sender, our best cold email software comparison shows which ones bundle warmup.
How long to warm up a new domain
The vendors agree on roughly two weeks at minimum. MailReach says at least 14 days, Instantly says 2 to 4 weeks and ideally 30 days, and Smartlead suggests 1 to 2 months for a brand-new domain. Keep warmup running after campaigns start, since every tool here is built to run alongside live sending.
Check the copy, not just the mailbox
Warmup builds sender reputation, but spammy wording can still push a warm mailbox into the promotions or spam folder. Run your email through our free spam word checker before you launch.
After warmup: handling the replies
Works with
Instantly and Smartlead from this list, plus Email Bison, PlusVibe, SendKit and ArcSend
Warm mailboxes land in the inbox, and that is when replies start. Interested leads, out-of-office notes and "talk to my colleague" messages arrive across every mailbox you warmed, and the meeting is lost if nobody answers within the day.
Revbound isn't a warmup tool, which is why it isn't ranked above. It reads replies from Instantly, Smartlead, Email Bison, PlusVibe, SendKit and ArcSend into one inbox, sorts each one with AI, drafts or sends the answer within 5 minutes, and books the meeting from times that are free on your Cal.com or Google Calendar.
Revbound inbox
Pick Revbound if
Replies come in across many warmed mailboxes
You want out-of-office leads followed up when they return
You want meetings booked from free calendar times
Honest limits
No warmup or sending
Doesn't read lemlist replies
Newer and smaller than the tools above
Plans are Solo $49, Agency $99 and Connector $149 a month, month to month with AI included. See Revbound plans for what each includes.
Pricing
Email warmup tool pricing compared
Tool
Entry plan, monthly
Warmup on entry plan
Next plan up
Yearly price
Cost for 10 mailboxes
Instantly
Growth $47
Unlimited accounts
Hypergrowth $107
Yearly option
$47 (sender included)
Smartlead
Base $39
Unlimited accounts, Foundation pool
Pro $94
Base $32
$39 (sender included)
Warmup Inbox
Basic $19 per inbox
75 emails a day
Pro $59 per inbox
Basic $15
Up to $190
TrulyInbox
Free, then Starter $29
200 emails a day, shared
Growth $99
Starter $22
$29 (200 a day shared)
Lemwarm
Essential $29 per mailbox
Not stated
Smart $49 per mailbox
Essential $24
$290
MailReach
$25 per mailbox
Up to 100 emails a day
$19.50 from 6 mailboxes
$20 per mailbox
About $223
Warmy
From $49
By volume
Not published
Not published
Not published
Monthly-billing list prices in USD. Warmup Inbox lowers its per-inbox price as you add inboxes, so $190 is the most 10 inboxes cost on Basic. MailReach at 10 mailboxes: 5 at $25 plus 5 at $19.50.
FAQ
Email warmup tool questions
What is the best email warmup tool?
If you send with Instantly or Smartlead, the best warmup tool is the one already in your plan, because both include unlimited warmup for every mailbox. For a standalone tool, Warmup Inbox is the cheapest per inbox at $19 a month, TrulyInbox suits many mailboxes because it prices by daily volume, and MailReach adds spam tests to every mailbox.
Do I need an email warmup tool?
You need warmup for any new mailbox or domain you plan to send cold email from, but you may not need a separate tool. Instantly, Smartlead and lemlist all include warmup in their plans. A standalone warmup tool is worth paying for when your sender has none or you want extra placement testing.
Is there a free email warmup tool?
TrulyInbox has a free forever plan that warms 1 account at 10 emails a day. Lemwarm is free for lemlist customers, and Instantly and Smartlead include warmup at no extra cost in their paid plans. Warmup Inbox and Warmy offer 7-day free trials with no card.
Is free email warmup safe?
Warmup from an established tool is generally safe when it ramps slowly and pauses on problems, which is how these vendors describe their systems. The risk with very cheap or free warmup networks is low-quality mailboxes in the pool. Keep daily warmup volume modest, watch bounce and spam rates, and stop if they climb.
How long should you warm up a new domain?
Plan on at least two weeks. MailReach recommends 14 days minimum, Instantly suggests 2 to 4 weeks and ideally 30 days, and Smartlead suggests 1 to 2 months for a brand-new domain. Keep warmup running after you start sending.
How do I check if my email is warmed up?
Send a test to a seed list and see where it lands. MailReach offers a free spam test you can run up to 3 times a day, Warmup Inbox includes an inbox placement test, and Warmy plans come with placement credits. Then watch bounce and spam rates on your first real campaigns before you raise daily volume.
Is TrulyInbox good for email warmup?
TrulyInbox is a good fit when you warm many mailboxes on one budget, because it allows unlimited accounts and prices by daily warmup volume, from $29 a month for 200 emails a day. It also has a free forever plan for 1 account at 10 emails a day. The catch is that the daily volume is shared across every connected account.
Does Instantly include email warmup?
Yes. Every Instantly plan, from Growth at $47 a month, includes unlimited email accounts and unlimited warmup. Instantly's warmup page says its network has over 1,000,000 real email accounts.
Does Revbound warm up email accounts?
No. Revbound handles the replies after warmup and sending. It reads replies from Instantly, Smartlead, Email Bison, PlusVibe, SendKit and ArcSend, sorts them with AI, answers interested leads and books meetings, from $49 a month with a 3-day free trial.
Instantly, Smartlead, Warmup Inbox, TrulyInbox, lemwarm, lemlist, MailReach and Warmy are trademarks of their owners, and Revbound is not affiliated with them. Prices are published list prices and can change, so confirm them on each vendor's pricing page before you buy. Choosing a sender too? See our list of Instantly alternatives.
Three days free
Inboxes warm, replies coming in?
Revbound sorts every reply from Instantly or Smartlead, answers the interested leads and books the meetings for you.
