Mail-Tester vs Skysnag
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 assessmentSkysnag compared with Mail-Tester
Adjacent rather than competing, and usefully so. Mail-Tester answers whether one message is technically clean, free, in under a minute, including whether SPF, DKIM, and DMARC pass on that send. Skysnag answers whether your domain is protected from everyone else sending as you, continuously, and fixes the records to make it so. The cheap sensible pattern for a small business is both: Mail-Tester for the pre-send check on each campaign, and an authentication platform standing behind the domain.
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 Skysnag if
Small and mid-sized organisations that need to reach DMARC enforcement rather than merely watch reports, especially those with many sending services, limited DNS expertise, or a customer, insurer, or auditor asking for evidence.
Side by side
13 attributes| Attribute | Mail-Tester | Skysnag |
|---|---|---|
| Category | Deliverability | Deliverability |
| Starting price | $0 (3 tests per 24 hours), then $10 per month for 50 tests | $39 per month (Monitor) (14 days 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. | Subscription by domain count and report-processing speed, with two published tiers and two quoted ones above them. Additional modules for verification and BIMI certification are sold alongside. |
| 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 | 14 days, no credit card required |
| 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. | Small and mid-sized organisations that need to reach DMARC enforcement rather than merely watch reports, especially those with many sending services, limited DNS expertise, or a customer, insurer, or auditor asking for evidence. |
| 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. | An afternoon to point reporting at Skysnag and start ingesting, then two to six weeks of running before a domain is ready to move to enforcement. The calendar is set by how long it takes to see every legitimate sender in the report stream, not by the software. |
| 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 by the standards of DMARC tooling, which is the point of the product. The dashboards are aimed at non-specialists, and the automation removes most of the DNS knowledge the category normally demands. |
| Platforms | Web application, JSON API, iframe embed | Web application, API |
| Compliance | None published | SOC 2 (AICPA), GDPR, CCPA, CSA, Cyber Essentials, Data Privacy Framework, IASME, PCI-DSS |
| Founded | 2014 | 2020 |
| Headquarters | France | San Francisco, California, United States |
| Ownership | Privately held; the operating company is not named publicly | Venture-backed |
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.
Skysnag
Strengths
- Automates the hard half of DMARC: discovering senders and maintaining the records, rather than only charting the reports.
- Handles SPF maintenance automatically, which addresses the ten-lookup limit that quietly breaks hand-edited records.
- The full protocol set in one product: DMARC, SPF, DKIM, BIMI, MTA-STS, and TLS-RPT.
- An unusually complete compliance posture for a small vendor, including SOC 2, Cyber Essentials, IASME, PCI-DSS, and the Data Privacy Framework.
Limitations
- No free tier, in a category where dmarcian, EasyDMARC, and PowerDMARC all offer one for a single domain.
- Monitor includes only two domains, which is tight for any organisation holding several brand or regional domains.
- The step from $39 to $249 is the steepest in the category, and buys processing speed and retention rather than more automation.
- Automated DNS editing is the product's premise, and some infrastructure teams will not delegate record control to a vendor on principle.
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.
Skysnag
Subscription by domain count and report-processing speed, with two published tiers and two quoted ones above them. Additional modules for verification and BIMI certification are sold alongside.
- MonitorFrom $39
- ComplyFrom $249
- ProtectCustom
- Skysnag SuiteCustom
Against the reporting-only tools in this category, Skysnag is expensive: EasyDMARC, PowerDMARC, and dmarcian all have free tiers and paid plans well under $39 that will show you the same aggregate reports. Against the cost of actually reaching enforcement, it is cheap. The work Skysnag automates, inventorying senders and maintaining records until the policy can safely move to reject, is the part that otherwise consumes weeks of an engineer's attention or never gets finished at all, and a domain stuck at p=none is providing visibility rather than protection. The compliance set is a genuine secondary argument for a small business facing security questionnaires. The weak point is the plan structure: two domains on Monitor is tight, and the leap to $249 arrives sooner than the feature list suggests.
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 profileSkysnag
Skysnag is the right purchase when your DMARC problem is that nothing is happening. Plenty of tools will show you aggregate reports, several of them free, and a domain can sit at p=none for years being thoroughly monitored and entirely unprotected. What Skysnag sells is the part in between: it finds the senders, writes the records, keeps them current, and moves the policy to enforcement without anyone filing DNS change requests. For a small business that has been asked to prove its domain is protected, the $39 Monitor tier plus a compliance set most vendors this size cannot match is a short, cheap route to yes, and the published nonprofit and startup discounts make it shorter. Two things should push you elsewhere. If you have DNS expertise and time, PowerDMARC at $12 for five domains or OnDMARC Express at $9 for four give you more domain coverage for less money. And if your estate is large enough to need Comply, the jump from $39 to $249 deserves a hard look at what real-time processing and five-year retention are actually worth to you.
Read the full Skysnag profileMail-Tester profile last reviewed 2026-09-20; Skysnag last reviewed 2026-09-20. Pricing is compiled from public sources and can change without notice. See our methodology.
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Frequently asked questions
6 questionsWhat is the difference between Mail-Tester and Skysnag?
Adjacent rather than competing, and usefully so. Mail-Tester answers whether one message is technically clean, free, in under a minute, including whether SPF, DKIM, and DMARC pass on that send. Skysnag answers whether your domain is protected from everyone else sending as you, continuously, and fixes the records to make it so. The cheap sensible pattern for a small business is both: Mail-Tester for the pre-send check on each campaign, and an authentication platform standing behind the domain.
Is Mail-Tester or Skysnag cheaper?
Mail-Tester starts at $0 (3 tests per 24 hours), then $10 per month for 50 tests. Skysnag starts at $39 per month (Monitor) (14 days 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. Skysnag pricing model: Subscription by domain count and report-processing speed, with two published tiers and two quoted ones above them. Additional modules for verification and BIMI certification are sold alongside.
Does Mail-Tester or Skysnag 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. Skysnag has no free plan. Trial terms: 14 days, no credit card required.
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 Skysnag?
Small and mid-sized organisations that need to reach DMARC enforcement rather than merely watch reports, especially those with many sending services, limited DNS expertise, or a customer, insurer, or auditor asking for evidence.
What are the best alternatives to Mail-Tester and Skysnag?
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.
