Mail-Tester vs MailStrike
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
Both sides assessedMail-Tester compared with MailStrike
Complementary rather than alternatives. MailStrike warms mailboxes with an AI Agent each, writing threads at send time, scores reputation daily, and includes a placement test per mailbox per month sent from your own account, from $18 a mailbox a month. Mail-Tester does no warming and no monitoring; it scores a single message on demand and costs nothing to use three times a day. The sensible pattern is both: Mail-Tester while you are drafting and fixing the template, a warming and monitoring platform standing behind the mailboxes that will send it.
MailStrike compared with Mail-Tester
Complementary layers rather than alternatives. Mail-Tester scores a single message against SpamAssassin, free three times a day, and reports what in the content, the HTML, the links, or the authentication cost points. MailStrike warms the mailboxes that will send it, scores reputation daily, and includes a placement test per mailbox per month from the sending account itself. Neither replaces the other: use the free score while the copy is still being edited, and a warming and monitoring platform behind the mailboxes for everything that happens after send.
Choose Mail-Tester if
Anyone who needs a fast, credible answer to whether a specific message is technically clean before sending it, and developers who want that answer inside their own product through an API or an embedded, white-labelled result page.
Choose MailStrike if
Outbound teams and agencies running fleets of mailboxes who want warming that is not templated, documented spam rescue for domains already in trouble, and a placement test on every mailbox, plus B2C senders who need seed-based placement and live spam rescue on a real campaign.
Side by side
13 attributes| Attribute | Mail-Tester | MailStrike |
|---|---|---|
| Category | Deliverability | Deliverability |
| Starting price | $0 (3 tests per 24 hours), then $10 per month for 50 tests | $18 per mailbox per month billed annually ($23 monthly) for the first five mailboxes (free trial) |
| Pricing model | Free for three tests every 24 hours with no account. Paid subscriptions are priced by monthly test volume, with one-time payment options alongside, and the per-test rate falls as volume rises. Quotas reset monthly and do not roll over. | Priced per mailbox per month on graduated rates: each mailbox is billed at the rate of the band it falls in, so the blended cost per mailbox falls as the fleet grows. Rates step down at 6, 11, 16, 21, 51, and 101 mailboxes, up to 200. Above that, and seed lists, are quoted. |
| Free plan | Three tests in any rolling 24 hours with no account and no card, results kept for seven days, plus free SPF, DKIM, DMARC, and BIMI lookup tools. | No |
| Free trial | No separate trial; the free three tests a day serve as the evaluation path and do not expire | No trial published. The free deliverability test is the no-cost entry point and needs a signup but no card |
| Best for | Anyone who needs a fast, credible answer to whether a specific message is technically clean before sending it, and developers who want that answer inside their own product through an API or an embedded, white-labelled result page. | Outbound teams and agencies running fleets of mailboxes who want warming that is not templated, documented spam rescue for domains already in trouble, and a placement test on every mailbox, plus B2C senders who need seed-based placement and live spam rescue on a real campaign. |
| Setup time | Under a minute for the free test, with nothing to install or connect. An API or white-label integration is a few hours of developer time. | Under two minutes per mailbox: one-click OAuth for Google Workspace and Microsoft 365, or an app password over SMTP and IMAP for Yahoo, Proton, iCloud, Zoho, Fastmail, and anything else. Onboarding is guided by the team. A fresh domain still needs the 21-day ramp before meaningful volume, with noticeable improvement around two weeks; seed list onboarding is arranged separately when that product is quoted. |
| Learning curve | Very low to run, moderate to interpret. The report itemises deductions clearly, but knowing which of them genuinely matter, and which are SpamAssassin being pedantic about a template, takes a little experience. | Low. Persona warming and monitoring are automatic after connection; the placement tester is a single form. DNS fix guides assume no prior deliverability knowledge. |
| Platforms | Web application, JSON API, iframe embed | Web app, MCP server, REST API (Custom plans) |
| Compliance | None published | CASA Tier 2 (assessed and validated by TAC Security), Google OAuth verified, Microsoft OAuth verified, GDPR-aligned processes |
| Founded | 2014 | 2026 |
| Headquarters | France | Poland |
| Ownership | Privately held; the operating company is not named publicly | Backed by IT Monks |
Strengths and limitations
Mail-Tester
Strengths
- Three genuinely free tests every 24 hours with no account, which is the lowest-friction real answer available anywhere in this category.
- Built on SpamAssassin, so deductions name a specific rule rather than an opaque proprietary score.
- Tests your actual sending path, because you send from the system you will really use rather than through a relay.
- Covers authentication, blacklists, links, HTML, and server configuration in one report rather than across four tools.
Limitations
- It scores a message against a filter; it does not test inbox placement at Gmail, Outlook, and Yahoo the way GlockApps, Unspam, or a seed-list product does.
- No monitoring of any kind. It answers when asked and watches nothing in between, so reputation drift is invisible to it.
- No warming, no sending, and no reputation management, so it is always one tool in a stack rather than the stack.
- The operators publish almost nothing about themselves: no company name, no founders, no location beyond being French, and no compliance documentation.
MailStrike
Strengths
- An AI Agent per mailbox composes its threads at send time from the company description, so there is no template for a filter to fingerprint, which is the property shared-network and configured-pattern tools cannot replicate.
- Seed lists are sold standalone and need no warming plan, which lets a B2C sender buy per-provider placement and live spam rescue on a real campaign without subscribing to the warming product at all.
- Placement tests send from the user's own connected account through the real campaign path, with no seed lists to copy and no codes to paste.
- Spam rescue is documented and logged per event, so a customer can see each time a warming email was pulled out of spam rather than take the outcome on trust.
Limitations
- Agent threads are English-only, so programs sending mainly in other languages should look at Warmy, which documents more than 30 languages, or Warmup Inbox and TrulyInbox at 12.
- No free plan and no advertised free trial; every tier on the pricing page starts from a booked call, with a free deliverability assessment as the evaluation path.
- Deliverability tests are metered per tier (a single test a month on Solo), pricing above 20 mailboxes is quoted, and the Seed Lists add-on is priced per customer rather than self-serve.
- Deliverability-focused by design: MailStrike sends no campaigns, so it always runs alongside a sending platform rather than replacing one.
Pricing compared
Mail-Tester
Free for three tests every 24 hours with no account. Paid subscriptions are priced by monthly test volume, with one-time payment options alongside, and the per-test rate falls as volume rises. Quotas reset monthly and do not roll over.
- Free$0
- 50 tests a month$10
- 500 tests a month$25
- 2,000 tests a month$80
- 7,500 tests a month$250
Judged as a free tool, Mail-Tester is the best value in this category and it is not close: three real tests a day, built on SpamAssassin, with no account, covers the entire pre-send checking need of a small sender at no cost. Judged as a paid product it is narrow but priced honestly, and the buyers who get the most from it are not individuals at all but products embedding the report through the API and white-label. What it does not do should decide the purchase: no placement testing at named providers, no monitoring, no warming. If the question is whether this specific message is technically clean, nothing is faster or cheaper. If the question is where your mail is landing at Gmail this week, you need GlockApps, Unspam, or a warming platform with testing built in.
MailStrike
Priced per mailbox per month on graduated rates: each mailbox is billed at the rate of the band it falls in, so the blended cost per mailbox falls as the fleet grows. Rates step down at 6, 11, 16, 21, 51, and 101 mailboxes, up to 200. Above that, and seed lists, are quoted.
- Mailboxes 1 to 5$18
- Mailboxes 6 to 10$16
- Mailboxes 11 to 15$14
- Mailboxes 16 to 20$11
- Mailboxes 21 to 50$9
- Mailboxes 51 to 100$7
- Mailboxes 101 to 200$5
- CustomQuoted
The September 2026 move to graduated per-mailbox rates changed who this is good value for. At one mailbox nothing moved: $18 a month, against $15 at Warmbox and Warmup Inbox and about $2 at InboxDoctor, and the agent architecture is what the premium buys. At six mailboxes the bill went from $45 to $106 and at twenty from $92 to $295, so teams that were buying a flat band and filling it have seen a real increase. Where the new model reads well is at scale, because the blended rate falls to about $9.15 a mailbox at a hundred and $7.08 at two hundred, which undercuts MailReach at $19.50 and Warmup Inbox at $15 while including a placement test per mailbox per month that both charge for. Judge it on the fleet you actually run rather than the headline: this is now among the cheapest options above fifty mailboxes and among the more expensive below ten.
Editorial verdict on each
Mail-Tester
Mail-Tester earns its place in any deliverability stack by being free, fast, and specific. Three tests a day with no account, a score out of ten backed by SpamAssassin, and a report that names the exact rule costing you points is the cheapest useful thing a sender can do before launching a campaign, and the paid tiers are honestly priced for the agencies and products that run it at volume. The API, white-labelling, and micro-payment resale explain why the tool turns up inside other vendors' products, and make it a genuine build-versus-buy answer for anyone adding deliverability checks to their own software. Understand the boundary before relying on it: this is a technical cleanliness check, not a placement test and not a monitor. A ten out of ten tells you nothing about which Gmail tab you landed in, and nothing at all about next week. Use it constantly, for free, alongside a warming and monitoring platform that covers what it deliberately does not.
Read the full Mail-Tester profileMailStrike
InnovationMailStrike's argument is that templated warming has stopped working, and its answer is to give every mailbox an agent rather than a configuration: a persona with its own reply rate, dwell time, active hours and typo chance, composing each thread at send time from the sender's own company description so there is no pattern to fingerprint. Whether that beats a well-configured shared network is not something a buyer can verify from outside, and the honest framing is that it is the most specific architectural claim in the category rather than a proven one. What is verifiable is the surrounding kit, and it is strong: documented spam rescue logged per event, a placement test included per mailbox per month where most rivals sell tests as credits, a daily reputation score with a 14-day trend, an AI assistant writing a daily summary per mailbox, broad provider coverage, and standalone seed lists for B2C senders. The September 2026 repricing is the thing to model before buying. A single mailbox still costs $18, but six went from $45 to $106 and twenty from $92 to $295, while the graduated rates make large fleets genuinely cheap at about $9.15 a mailbox at a hundred and $7.08 at two hundred. Below ten mailboxes this is now one of the more expensive options in the category; above fifty it is one of the cheapest. English-only warming remains the hard limit, and there is no trial, so the free deliverability test and a booked call are the way in.
Read the full MailStrike profileMail-Tester profile last reviewed 2026-09-20; MailStrike last reviewed 2026-09-26. 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 Mail-Tester and MailStrike?
Complementary rather than alternatives. MailStrike warms mailboxes with an AI Agent each, writing threads at send time, scores reputation daily, and includes a placement test per mailbox per month sent from your own account, from $18 a mailbox a month. Mail-Tester does no warming and no monitoring; it scores a single message on demand and costs nothing to use three times a day. The sensible pattern is both: Mail-Tester while you are drafting and fixing the template, a warming and monitoring platform standing behind the mailboxes that will send it.
Is Mail-Tester or MailStrike cheaper?
Mail-Tester starts at $0 (3 tests per 24 hours), then $10 per month for 50 tests. MailStrike starts at $18 per mailbox per month billed annually ($23 monthly) for the first five mailboxes (free trial). The billing models differ, so the entry price is rarely the whole cost. Mail-Tester pricing model: Free for three tests every 24 hours with no account. Paid subscriptions are priced by monthly test volume, with one-time payment options alongside, and the per-test rate falls as volume rises. Quotas reset monthly and do not roll over. MailStrike pricing model: Priced per mailbox per month on graduated rates: each mailbox is billed at the rate of the band it falls in, so the blended cost per mailbox falls as the fleet grows. Rates step down at 6, 11, 16, 21, 51, and 101 mailboxes, up to 200.
Does Mail-Tester or MailStrike have a free plan?
Mail-Tester has a free plan. Three tests in any rolling 24 hours with no account and no card, results kept for seven days, plus free SPF, DKIM, DMARC, and BIMI lookup tools. Trial terms: No separate trial; the free three tests a day serve as the evaluation path and do not expire. MailStrike has no free plan. Trial terms: No trial published. The free deliverability test is the no-cost entry point and needs a signup but no card.
Who should choose Mail-Tester?
Anyone who needs a fast, credible answer to whether a specific message is technically clean before sending it, and developers who want that answer inside their own product through an API or an embedded, white-labelled result page.
Who should choose MailStrike?
Outbound teams and agencies running fleets of mailboxes who want warming that is not templated, documented spam rescue for domains already in trouble, and a placement test on every mailbox, plus B2C senders who need seed-based placement and live spam rescue on a real campaign.
What are the best alternatives to Mail-Tester and MailStrike?
SaaSTracker profiles 23 products in Email Deliverability & Warming. The Summer 2026 awards in the category went to MailReach (Category Leader), GlockApps (Best Value), InboxDoctor (Momentum). Every profile is compiled from primary sources, so a shortlist can be built from pricing, limitations, and fit rather than from star ratings.
