InboxDoctor vs Warmy
An independent, review-free comparison compiled by the SaaSTracker editorial team. Both products are profiled in full, and neither can pay for placement here.
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The short answer
Editorial assessmentInboxDoctor compared with Warmy
Warmy covers marketing and transactional senders on ESPs as well as sales mailboxes, with a broader automation story and higher pricing. InboxDoctor is focused on per-mailbox warming for outbound plus a separate high-volume B2C ladder. Choose Warmy for ESP-side sending and a wider platform; choose InboxDoctor for cheap per-mailbox ramping of sales infrastructure.
Choose InboxDoctor if
Cold outbound teams and agencies running many sending mailboxes who want the cheapest transparent per-mailbox warming available, with placement testing bought as needed rather than bundled into a larger subscription.
Choose Warmy if
Founders, small teams, and agencies that want reliable automated warm-up plus basic deliverability monitoring at a value price, including for ESP-based senders no one else warms.
Side by side
13 attributes| Attribute | InboxDoctor | Warmy |
|---|---|---|
| Category | Deliverability | Deliverability |
| Starting price | $2 per mailbox per month (B2B Starter) (7 days trial) | Not published; volume-based quote after a 7-day trial (free plan available) |
| Pricing model | Per-mailbox monthly subscription for B2B warming with a separate high-volume B2C ladder, plus credit packs for placement and health testing. | Quote-only as of September 2026. The pricing page now shows three plan shapes, B2B Sender, B2C Sender, and Custom, all described as volume-based with no figures published. A seven-day trial with no card is the only self-serve way in. |
| Free plan | No | Free deliverability test and domain health checkers (no warming). |
| Free trial | 7 days, no credit card required | 7 days, no credit card required |
| Best for | Cold outbound teams and agencies running many sending mailboxes who want the cheapest transparent per-mailbox warming available, with placement testing bought as needed rather than bundled into a larger subscription. | Founders, small teams, and agencies that want reliable automated warm-up plus basic deliverability monitoring at a value price, including for ESP-based senders no one else warms. |
| Setup time | Fifteen minutes to connect a mailbox and start warming. Reaching meaningful volume takes three to six weeks of ramping, which is the real timeline and cannot be compressed by paying more. | Minutes per mailbox; ESP connections take a bit longer (API keys, DNS). New domains need 3-4 weeks of warming before real volume. |
| Learning curve | Low. Connect mailboxes, choose a daily volume, and let it run. The judgement required is not operational but strategic: deciding whether warming is appropriate for your situation at all, and resisting the temptation to treat a good warming score as permission to send badly. | Low, the automation-first design targets non-experts; dashboards explain themselves. |
| Platforms | Web application, Google Workspace connection, Microsoft 365 connection, SMTP and IMAP connection | Web app, REST API (upper tiers) |
| Compliance | GDPR | GDPR-aligned processes |
| Founded | 2024 | 2021 |
| Headquarters | Wilmington, Delaware, United States | Tel Aviv, Israel |
| Ownership | Privately held and unfunded | Privately held |
Strengths and limitations
InboxDoctor
Strengths
- The cheapest published per-mailbox warming rate in the category, at $2 a mailbox for a thirty-a-day ramp.
- Completely transparent pricing that is trivial to model at any mailbox count, unlike volume-tier competitors.
- Google Postmaster integration included on every B2B tier including the $2 plan, giving you Google's own view of your domain reputation alongside the warming.
- Custom templates and language selection on all tiers, so warming content can resemble your real mail rather than generic filler.
Limitations
- Automated warming is contested practice. It manufactures engagement that does not correspond to real correspondence, mailbox providers have become better at detecting reciprocal warming networks, and Google has publicly discouraged it. Treat it as a volume-ramp discipline for genuinely new mailboxes, not a fix for bad sending.
- Network composition and quality cannot be independently verified by a buyer, here or at any warming vendor; the description of the network as human-powered is the vendor's claim rather than an audited fact.
- Per-mailbox pricing scales linearly, so large sending estates get expensive relative to volume-priced competitors like TrulyInbox.
- No DMARC aggregate report monitoring, so it says nothing about who else sends as your domain and offers no path to an enforced policy.
Warmy
Strengths
- Warms ESP/infrastructure senders (SendGrid, Mailgun, SES), nearly unique in the category.
- Genuinely automated: good default behavior with minimal configuration required.
- Bundled DNS validation with record generation removes the most common self-inflicted failures.
- Free testing tools lower the barrier to diagnosing problems before paying.
Limitations
- Less manual control over warming behavior than operator-oriented rivals.
- Network curation is less transparent than MailReach's quality-first positioning.
- Continuous monitoring is lighter than Folderly's ops suite.
- Per-mailbox price at higher volume tiers climbs quickly.
Pricing compared
InboxDoctor
Per-mailbox monthly subscription for B2B warming with a separate high-volume B2C ladder, plus credit packs for placement and health testing.
- Starter (B2B)$2
- Growth (B2B)$4
- Enterprise (B2B)$6
- Essential, Pro, and Brand (B2C)$120, $240, and $720
On the warming axis alone, InboxDoctor is the cheapest transparent option published anywhere in this category. Two dollars a mailbox for a thirty-a-day ramp, with Google Postmaster data and custom templates included at that price, undercuts MailReach, Warmbox, and Mailivery substantially. The linear model is honest and easy to budget, and it is also the weakness: at fifty mailboxes, TrulyInbox's volume-based pricing with unlimited accounts is likely to be cheaper, and the gap widens above that. Credit-based placement testing is a fair structure that keeps the base price low. The real question is not price at all but whether automated warming works well enough to be worth any money, which is a judgement no vendor's pricing page can settle.
Warmy
Quote-only as of September 2026. The pricing page now shows three plan shapes, B2B Sender, B2C Sender, and Custom, all described as volume-based with no figures published. A seven-day trial with no card is the only self-serve way in.
- B2B SenderNot published
- B2C SenderNot published
- CustomCustom
Value is now hard to judge from the outside, which is itself the finding. Warmy used to publish a $49 entry rate that bundled warming, DNS tooling, and basic testing for less than those parts cost separately; that number is gone, and the page asks for a demo instead. What can still be assessed is the capability set, which is the broadest in the category: a million-mailbox network, a rotating 500,000-address US seed list, an AI co-pilot, Postmaster data, verification, and DMARC, all listed under every plan rather than gated. The free checkers remain genuinely useful, and the seven-day no-card trial means you can test the product before you know what it costs. Buyers who need a published number to budget against should shortlist MailReach at $19.50 a mailbox or MailStrike at $45 for six, and treat Warmy as the quote you get when volume is large enough to justify the call.
Editorial verdict on each
InboxDoctor
MomentumInboxDoctor is the cheapest transparent warming product on the market, and for a small outbound team the arithmetic is hard to argue with: five mailboxes ramping at fifty emails a day for $20 a month, with Google Postmaster data and custom templates included, and placement tests available as credits when you need evidence. The per-mailbox model is honest and easy to budget, and it is also the limitation, since linear scaling makes TrulyInbox's volume pricing cheaper above roughly twenty mailboxes. Two larger cautions apply. The company was founded in 2024, is unfunded, and asks for access to your production sending mailboxes, which is a real trust decision. And warming itself is contested practice that mailbox providers increasingly detect and Google has discouraged, so it should be used to ramp genuinely new mailboxes rather than to make bad sending work. Within those limits, this is a well-priced tool that does exactly one job.
Read the full InboxDoctor profileWarmy
Warmy wins the value slot in deliverability: automation good enough to trust, DNS tooling that prevents rookie disasters, and, its ace, warming for ESP senders nobody else serves. Cold-email purists chasing the last percentile of network quality will pay MailReach's premium, and ops teams will graduate to Folderly, but for most senders standing up or maintaining reputation, Warmy is the sensible default.
Read the full Warmy profileInboxDoctor profile last reviewed 2026-09-20; Warmy last reviewed 2026-09-20. Pricing is compiled from public sources and can change without notice. See our methodology.
The best in Email Deliverability & Warming
23 trackedEmail deliverability and warming tools build and protect sender reputation by exchanging positive engagement signals between real inboxes, and by monitoring where a sender's mail actually lands.
The most complete pairing of warming network quality with actionable spam-placement testing in the category.
A free tier with real test credits and a $59 entry point put audit-grade placement, DMARC, and blacklist visibility within any sender's budget.
Founded in 2024, InboxDoctor undercuts the entire warming market at $2 per mailbox with Google Postmaster integration included on every tier.
Rethought warming twice in one product: an AI Persona behind every mailbox in place of detectable network patterns, and a seedlist of thousands of trusted inboxes that campaigns are pre-sent to at scale for delivery feedback and engagement before launch.
A placement and spam test takes under ten minutes with no DNS change or mailbox connection, and the itemized score explains every fix in plain language.
Frequently asked questions
6 questionsWhat is the difference between InboxDoctor and Warmy?
Warmy covers marketing and transactional senders on ESPs as well as sales mailboxes, with a broader automation story and higher pricing. InboxDoctor is focused on per-mailbox warming for outbound plus a separate high-volume B2C ladder. Choose Warmy for ESP-side sending and a wider platform; choose InboxDoctor for cheap per-mailbox ramping of sales infrastructure.
Is InboxDoctor or Warmy cheaper?
InboxDoctor starts at $2 per mailbox per month (B2B Starter) (7 days trial). Warmy starts at Not published; volume-based quote after a 7-day trial (free plan available). The billing models differ, so the entry price is rarely the whole cost. InboxDoctor pricing model: Per-mailbox monthly subscription for B2B warming with a separate high-volume B2C ladder, plus credit packs for placement and health testing. Warmy pricing model: Quote-only as of September 2026. The pricing page now shows three plan shapes, B2B Sender, B2C Sender, and Custom, all described as volume-based with no figures published. A seven-day trial with no card is the only self-serve way in.
Does InboxDoctor or Warmy have a free plan?
InboxDoctor has no free plan. Trial terms: 7 days, no credit card required. Warmy has a free plan. Free deliverability test and domain health checkers (no warming). Trial terms: 7 days, no credit card required.
Who should choose InboxDoctor?
Cold outbound teams and agencies running many sending mailboxes who want the cheapest transparent per-mailbox warming available, with placement testing bought as needed rather than bundled into a larger subscription.
Who should choose Warmy?
Founders, small teams, and agencies that want reliable automated warm-up plus basic deliverability monitoring at a value price, including for ESP-based senders no one else warms.
What are the best alternatives to InboxDoctor and Warmy?
SaaSTracker profiles 23 products in Email Deliverability & Warming. The Summer 2026 awards in the category went to MailReach (Category Leader), GlockApps (Best Value), MailStrike (Innovation). Every profile is compiled from primary sources, so a shortlist can be built from pricing, limitations, and fit rather than from star ratings.
