The Warmbox Insider’s Guide
Everything we know about Warmbox in one document: what it costs, its grades, getting a refund, getting help and what else to look at. Read it here, or keep a copy.
Warmbox
The Insider’s Guide
Email warm-up through a private network of inboxes
Every plan, grade, refund rule and rival among cold outreach tools, read from Warmbox’s own pages.
Made by Warmbox · checked Nov 12, 2026 · toolgpa.com
Contents
- 01WelcomeWhat it is, who it suits, its grades and the ten things to know first
- 02What it costsEvery plan, the free plan, ways to pay less and how prices have moved
- 03What it doesIts main features, where it runs, what it works with and who makes it
- 04Where it standsIts grades against its category, and whether to keep it or make your own
- 05The alternativesThe tools it is most often weighed against, side by side
- 06Quick answersThe questions people ask about it, each answered in a line or two
- 07About ToolGPAWho made this guide, what else is on the site, and how to cite it
ToolGPA put this guide together from Warmbox’s own pages, its app-store listings and our grades. Every fact in it is on Warmbox’s page too, where it is kept up to date. Checked Nov 12, 2026.
Part 01 · Overview
Welcome
What it is, who it suits, its grades and the ten things to know first
1.8
GPA, above 5 of the 47 other cold outreach tools we grade
Warmbox is an email warm-up service. It exchanges automated messages between your mailbox and a network of its own inboxes, opens and replies to them, and pulls warm-up mail out of spam, with the aim of building sender reputation. It connects to Gmail, Outlook and other providers, and includes DNS and blacklist checks and a deliverability dashboard.
To get you started, here are 8 things to know about Warmbox, taken from its own pages and our grades.
You connect each mailbox and pick a warm-up profile, which is a bit of setup per inbox.
- 1
Best for warming up a single cold-email inbox
Warmbox sends warm-up traffic between mailboxes so a new sending address builds reputation.
- 2
Paid plans start at $15 a month
As its pricing page puts it: $15 per month for 1 inbox (the page's other billing toggle shows $19).
- 3
It runs on Web
Web.
- 4
Automated warm-up traffic
Sends and answers messages with a private inbox network, marks them as favorites and removes them from spam.
- 5
Warm-up profiles
Growth, flat or random volume patterns, a warm-up schedule and fully custom settings.
- 6
Realistic content
The page says replies are written to look human, using GPT-4 and a hybrid approach.
- 7
A 1.8 GPA, above 5 of 47
That is against the other cold outreach tools we grade, on value, the free plan, features, ease of use and platforms.
- 8
Keep it
To replace Warmbox you would be making a network of real inboxes that open and answer your emails. That is not a weekend's work, with an AI app builder or without one.
Warmbox at a glance
- Pricing
- Paid, from $15 per month for 1 inbox (the page's other billing toggle shows $19)
- Free plan
- No
- Free trial
- None stated
- Runs on
- Web
- Made by
- Warmbox
- Category
- Cold Outreach
- Our grade
- 1.8 GPA, weak
The report card
Best for warming up a single cold-email inbox
Warmbox sends warm-up traffic between mailboxes so a new sending address builds reputation. It warms inboxes and nothing else, the vendor says results take 15 to 30 days, and anything bigger than a few inboxes means a custom plan.
| Subject | Grade | Comment |
|---|---|---|
| Value for money | B | $15 a month for 1 inbox is inside the cheapest quarter of cold outreach tools ($25), but the 3-inbox plan is $69 and 6 inboxes is $139. The page's other billing toggle shows $19. |
| Free plan and trial | F | No free plan and no trial is listed. A free blacklist and DNS checker is the only free part. |
| Features | D | It warms inboxes with automated traffic, profiles and monitoring. It does not find leads or send campaigns, so it needs a sending tool next to it. |
| Ease of use | C | No store rating on record. You connect each mailbox and pick a warm-up profile, which is a bit of setup per inbox. |
| Platforms and integrations | B | Web only, but it works with Gmail, Google Workspace, Microsoft 365, Yahoo, SendGrid, Mailgun, Amazon SES and Zoho inboxes. |
An A is worth 4 points, a B 3, a C 2, a D 1 and an F nothing. The GPA is the average of the five.
Who Warmbox is for
- Fits if you send cold email from one or two new mailboxes and want a warm-up run in the background
- Works for agencies that connect many client inboxes and will ask for a custom plan
Who it is not for
- Skip it if you want a free try, because there is no trial or free plan
- Tight if you run more than 6 inboxes, as plans stop there and larger setups are custom
- Pricey if you add inboxes: $15 for 1 inbox becomes $69 for 3
- Watch out: the vendor says warm-up usually needs 15 to 30 days of uninterrupted running before results show
- Watch out: the pricing page doesn't say which billing period each of its two price sets applies to
Good to know
Good for
- Cold emailers warming a handful of new mailboxes
- Agencies that need several client accounts in one place
- Senders using providers beyond Gmail, including SMTP mailboxes
Worth knowing
- The pricing page does not state which billing period each of its two price sets applies to; the default view shows $15 for Solo and the other toggle shows $19.
- Plans are sized by the number of inboxes (1, 3 or 6) and by emails a day, so larger setups need a custom plan.
- The vendor says warm-up usually takes 15 to 30 days of uninterrupted warming before results show.
- It warms mailboxes only; it does not send campaigns or find leads.
Part 02 · Pricing
What it costs
Every plan, the free plan, ways to pay less and how prices have moved
$15
A month to start
Warmbox is a paid product, starting at $15 per month for 1 inbox (the page's other billing toggle shows $19).
A free blacklist and DNS checker is the only free part.
Solo
$15
per month for 1 inbox, billing basis unclear
1 inbox warmed at up to 50 emails a day, 1 member and premium support. The page's other toggle lists $19.
Start-up
$69
per month for 3 inboxes, billing basis unclear
3 inboxes at up to 250 emails a day, 3 team members and premium support. The other toggle lists $79.
Growth
$139
per month for 6 inboxes, billing basis unclear
6 inboxes at up to 500 emails a day, 6 team members and enterprise support. The other toggle lists $159.
Team
Custom
Custom plans for larger sending volumes, quoted through the vendor's chat.
Read from warmbox.ai on Nov 12, 2026.
Part 03 · Features
What it does
Its main features, where it runs, what it works with and who makes it
1
Place it runs: Web
Email warm-up through a private network of inboxes. Here is what it does, as its own site describes it, and what it covers: AI features, reports, inbox warm-up.
It warms inboxes with automated traffic, profiles and monitoring.
- Automated warm-up traffic
- Sends and answers messages with a private inbox network, marks them as favorites and removes them from spam.
- Warm-up profiles
- Growth, flat or random volume patterns, a warm-up schedule and fully custom settings.
- Realistic content
- The page says replies are written to look human, using GPT-4 and a hybrid approach.
- Checks and monitoring
- A live email checker for DNS and blacklists, spam score monitoring and a reporting dashboard.
- Many inbox types
- Gmail and Google Workspace by OAuth, Microsoft 365, Yahoo, iCloud, AOL, Zoho, SendGrid, Mailgun, Amazon SES and any SMTP mailbox.
- Agency use
- Multi-account support for agencies and team members on every plan.
Where it runs
- Web
What it works with
- Gmail
- Google Workspace
- Microsoft 365
- Yahoo
- SendGrid
- Mailgun
- Amazon SES
- Zoho
Warmbox is made by Warmbox.
Part 04 · Standing
Where it stands
Its grades against its category, and whether to keep it or make your own
5/47
Other cold outreach tools it is graded above
Warmbox's GPA of 1.8 is higher than 5 of the 47 other cold outreach tools we grade, and level with 3.
It stands best on value for money (B, above 29 of 47) and worst on free plan and trial (F, above 0).
Its paid plans start at $15 a month, against a middle price of $39 for the category: 5 of the 43 others that charge start lower.
On features, ease of use and platforms it scores 2.0 out of 4. 1 tool scores higher and costs less.
Each grade against the category
Every bar is all 48 cold outreach tools we grade, cut by the letter each got. Warmbox’s own letter is outlined.
- BValue for moneyAbove 29 of 47
- FFree plan and trialAbove 0 of 47
- DFeaturesAbove 0 of 47
- CEase of useAbove 0 of 47
- BPlatforms and integrationsAbove 9 of 47
Price against what you get
Each dot is one of 44 cold outreach tools. Further left costs less; higher up scores better on features, ease of use and platforms. Warmbox is the marked dot.
What paid plans start at, a month (each step along is roughly double) →
Keep it, or make your own?
Whether this is something you could build for yourself with an AI app builder, and what you would give up.
Keep it
To replace Warmbox you would be making a network of real inboxes that open and answer your emails. That is not a weekend's work, with an AI app builder or without one.
That makes this kind of software worth paying for, not this one in particular: 39 of the 47 other cold outreach tools grade higher. It costs $180 a year.
What you could make
- Reports: an app builder makes this well.
What you could not
- A network of real inboxes that open and answer your emails.
- It plugs into other products, Gmail, Google Workspace and Microsoft 365 among them.
- AI features, unless you pay a model provider for each request yourself.
What this rests on. Warmbox’s listing: what it does, where it runs, what it plugs into and what it costs. It is a judgement about the kind of software this is. We have not built a replacement for it, and making your own means looking after it too. How we decide, and every tool’s verdict.
Part 05 · Alternatives
The alternatives
The tools it is most often weighed against, side by side
Mailivery, Folderly, Instantly, Smartlead and Saleshandy
The 5 tools Warmbox is most often weighed against, with where each one differs from it.
- 2.2GPA
Mailivery
Free trial · from $21.75/mo
Email warm-up priced by daily volume, with unlimited mailboxes.
- Warmbox also covers reports.
- Mailivery also covers email verification.
- 2.0GPA
Folderly
Free plan · from $79/mo
Email deliverability tools: placement tests, fixes and monitoring.
- Folderly has a free plan. Warmbox does not.
- Warmbox also covers inbox warm-up.
- Folderly also covers dMARC.
- 2.6GPA
Instantly
Free trial · from $37.6/mo
Cold email from unlimited inboxes, priced by emails and contacts.
- Warmbox also covers reports and inbox warm-up.
- Instantly also covers workflow automation, AI agents and email campaigns.
- 2.6GPA
Smartlead
Free trial · from $32/mo
High-volume cold email with unlimited mailboxes and client workspaces.
- Only Smartlead lists iOS and Android apps.
- Warmbox also covers reports and inbox warm-up.
- Smartlead also covers sales pipeline, AI agents and email campaigns.
- 2.8GPA
Saleshandy
Free trial · from $34/mo
Cold email sequences with a B2B lead database in every plan.
- Warmbox also covers reports and inbox warm-up.
- Saleshandy also covers shared inbox and email campaigns.
Part 06 · Questions
Quick answers
The questions people ask about it, each answered in a line or two
12
Questions, each answered in a line or two
The short version of everything above, for when you only need the answer. Each one is told in full in its part of the guide.
Is Warmbox free?
No. Warmbox is a paid product, starting at $15 per month for 1 inbox (the page's other billing toggle shows $19).
How much does Warmbox cost?
Warmbox lists 4 plans. Solo: $15 per month for 1 inbox, billing basis unclear.
What platforms does Warmbox work on?
Warmbox is available on Web.
Does Warmbox have an Android app?
No Android app was listed when its pages were read on Nov 12, 2026. Warmbox is listed for Web.
Does Warmbox have an iPhone app?
No iPhone app was listed when its pages were read on Nov 12, 2026. Warmbox is listed for Web.
Is Warmbox open source?
Warmbox is not described as open source on its own site, as read on Nov 12, 2026.
What does Warmbox integrate with?
Warmbox's listing names Gmail, Google Workspace, Microsoft 365, Yahoo, SendGrid, Mailgun, Amazon SES and Zoho.
Who makes Warmbox?
Warmbox is made by a company of the same name.
What are the alternatives to Warmbox?
The closest alternatives to Warmbox in our directory are Mailivery, Folderly, Instantly, Smartlead and Saleshandy.
How does Warmbox compare with other cold outreach tools?
Warmbox's GPA of 1.8 is higher than 5 of the 47 other cold outreach tools we grade, and level with 3.
Is Warmbox good value for money?
ToolGPA grades Warmbox B for value for money. Its paid plans start at $15 a month, against a middle price of $39 for the category: 5 of the 43 others that charge start lower.
Could I make my own version of Warmbox?
To replace Warmbox you would be making a network of real inboxes that open and answer your emails.
Where this guide comes from
The prices, plans, platforms and features were read from Warmbox’s own pages on Nov 12, 2026, and the grades were given on Nov 12, 2026. Graded from this listing, whose facts were read from Warmbox's own pages on 12 November 2026. Not based on using the product, and shorter than our full reviews.
Every tool we list gets five grades, A to F, each with its reason, and a GPA that averages them. How each is decided is at toolgpa.com/grades. This guide is ToolGPA’s own work; it is not made, paid for or approved by Warmbox. Prices change, so check warmbox.ai before you buy.
Part 07 · About
About ToolGPA
Who made this guide, what else is on the site, and how to cite it
5,038
Tools graded, in 95 categories
ToolGPA grades software the way a school report grades a pupil: five subjects, a letter for each with the reason written beside it, and a GPA that averages them. Prices, plans and platforms are read from each maker’s own pages and dated, so you always know how fresh a figure is.
Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Every tool on the site has a guide like this one, free to download and pass on. It all lives at toolgpa.com.
5,038
tools graded
95
categories
739
price changes on record
579
apps priced in 12 countries
What else is on toolgpa.com
- Warmbox, kept up to dateEverything in this guide, with prices and grades as they are todaytoolgpa.com/tools/warmbox
- How grades are givenThe rules behind every letter and every GPAtoolgpa.com/grades
- Value chartsWhat each tool costs against what it scores, for every categorytoolgpa.com/charts
- CompareAny two tools side by side, plan by plantoolgpa.com/compare
- Price changesEvery price rise and cut on record, each with its sourcetoolgpa.com/price-changes
- Prices by countryWhat apps cost on the App Store in 12 countriestoolgpa.com/prices-by-country
- Pay lessEvery public discount: yearly billing, students, nonprofitstoolgpa.com/save
- Keep or makeWhich tools are worth paying for, and which you could build yourselftoolgpa.com/keep-or-make
Scan for the live page
Prices and grades as they are today
Quoting this guide?
Please name ToolGPA and link to the live page, so readers can check the figures for themselves:
ToolGPA, "Warmbox: The Insider's Guide", checked Nov 12, 2026. https://toolgpa.com/tools/warmbox
Know someone choosing between cold outreach tools?
Send them this guide: toolgpa.com/tools/warmbox/guide
ToolGPA elsewhere: youtube.com/@toolgpa
See our other guides
The best-graded cold outreach tools after Warmbox, each with an Insider's Guide of its own.
- Cold Outreach Insider's GuideEvery one of the 48 cold outreach tools we grade, compared
- lemlist Insider's GuideCold email and LinkedIn sequences with a built-in lead database2.8 GPA
- Salesforge Insider's GuideCold email and LinkedIn sequences with AI-written messages2.8 GPA
- Saleshandy Insider's GuideCold email sequences with a B2B lead database in every plan2.8 GPA
Choosing software? Every tool graded, every price dated.
Compare tools at toolgpa.com ›Everything in this guide is ToolGPA’s own summary of what Warmbox’s pages, its app-store listings and public reviews said on the dates shown. Grades are our judgement under the rules at toolgpa.com/grades. Every grade, review and ranking on ToolGPA is our own judgement. No company can pay for a grade or change one. Warmbox is a trademark of its owner, and this guide is not made, paid for or approved by Warmbox. Prices and plans change: check warmbox.ai before you buy.