MailerCheck
A cent-per-check verifier from the MailerLite family, with placement and content testing bolted on
MailerCheck is an email verification and deliverability testing service created by the team behind MailerLite that cleans email lists at $0.01 per address on non-expiring pay-as-you-go credits, verifies new signups in real time via API, and offers credit-metered inbox placement tests and content analysis (Email Insights) for senders who want to protect deliverability without a monthly subscription.
Overview
MailerCheck is the measurement-and-hygiene entry point of this category: no warming network, no monitoring subscription, just a credit meter. One credit verifies one address, a full content analysis (Email Insights) or an inbox placement test costs 200 credits, and credits run $0.01 each with a 1,000-credit minimum, so the practical entry price is $10 and the credits never expire. New accounts get 10 free credits to test verification without a card. That structure makes it one of the few tools in the category a sender can use twice a year without paying for the other ten months.
The verification core does what marketers need before a send: flags invalid addresses, syntax errors, dead mailboxes, catch-alls, and other bounce risks across a pasted address, an uploaded list, or a native sync from MailerLite, Mailchimp, ActiveCampaign, GetResponse, ConvertKit, Zapier, or Make, with automated recommendations on what to delete or segment. A real-time verification API blocks bad addresses at the signup form, which is cheaper than cleaning them out later. MailerCheck pairs that with a 98 percent-plus delivery-rate claim for verified lists, standard marketing math in this niche and about as verifiable as competitors' equivalents.
What separates MailerCheck from bare verifiers is the testing layer, and what separates it from GlockApps is depth. Email Insights runs campaign content through spam-word, code-quality, broken-link, and blocklist checks; Inbox Placement predicts whether a message reaches the inbox or spam across major providers like Gmail, Yahoo, and AOL. Both are useful pre-send checks, neither matches a dedicated seed-panel and DMARC platform. Behind the product sits the MailerLite organization, founded in Vilnius, Lithuania and acquired by Polish email-infrastructure group Vercom S.A. for $90M in 2022, which gives MailerCheck more institutional backing than most of the micro-vendors in this category.
Best for
Newsletter senders, lifecycle marketers, and small teams on ESPs like MailerLite or Mailchimp who want cheap, non-expiring, pay-as-you-go list verification with occasional placement and content checks, and no monthly deliverability subscription to justify.
Not the right fit for
- Cold-email teams needing warm-up; MailerCheck has no warming network at all, so outbound senders building reputation need a Warmbox, Mailivery, or Warmup Inbox alongside it.
- Deliverability professionals needing deep diagnostics; there is no DMARC analytics, no continuous blacklist monitoring product, and the placement test is a prediction across major providers, not a GlockApps-grade seed panel with per-filter scoring.
- B2B outbound teams verifying enterprise contacts; catch-alls are flagged rather than conclusively resolved, the exact segment where a specialist like Allegrow earns its premium.
- High-frequency testers; at 200 credits ($2) per Insights or Placement run the meter is fair for occasional checks, but teams testing daily will do better on a flat-rate testing subscription.
How it works
- 1
You buy credits (minimum 1,000 for $10) and spend them across the tools: 1 credit per address verified, 200 credits per Email Insights analysis, 200 credits per Inbox Placement test. Credits do not expire, so occasional senders can buy once and draw down over months.
- 2
For list verification, you paste addresses, upload a file, or connect an ESP integration; MailerCheck classifies each address (valid, invalid, syntax error, catch-all, and other risk categories) and returns automated recommendations, typically deleting hard invalids and segmenting risky addresses. Verified lists feed back into the connected ESP for sending.
- 3
The real-time API sits at the point of collection: as a signup form submits, the address is verified before it enters the list, keeping typos, disposables, and junk out of the database instead of cleaning them after they have already damaged a campaign's bounce rate.
- 4
Before a send, Email Insights analyzes the campaign itself, spam-trigger language, malformed HTML, broken links, and blocklist exposure, while an Inbox Placement test predicts where the message will land across major providers. Usage reports then track uploads, integrations, and API activity over time so list-health work is visible rather than ad hoc.
Feature breakdown
19 features in 5 modulesEmail list verification
The core product: classify every address on a list before it costs you bounces.- Bulk list verification
- Upload a file or sync from a connected ESP and every address is classified at 1 credit each, with results returned as downloadable, segmented lists.
- Single address check
- Paste one address for an instant verdict, useful for spot checks and support workflows.
- Risk classification
- Flags invalid addresses, syntax errors, dead and full mailboxes, catch-alls, and other bounce risks rather than returning a bare pass/fail.
- Automated recommendations
- Post-verification guidance on what to delete, keep, or segment turns raw classifications into a list-maintenance action plan.
- Delivery-rate claim
- MailerCheck advertises 98 percent-plus delivery rates for verified lists, a self-reported benchmark consistent with category norms.
Real-time verification API
Stop bad addresses at the door instead of cleaning them out later.- Point-of-collection verification
- The API verifies addresses as they are collected on signup forms, blocking typos, disposables, and junk before they enter the database.
- Same credit meter
- API verification draws from the same credit balance as bulk cleaning, one credit per check, with no separate API subscription.
- Programmatic list processing
- Lists can be submitted and results retrieved via API for teams automating hygiene inside their own pipelines.
Email Insights (content testing)
Pre-send analysis of the campaign itself, not just the list.- Spam-word analysis
- Flags phrasing and subject-line patterns associated with content filtering before the campaign goes out.
- Code and formatting checks
- Detects poorly formed HTML and formatting problems that correlate with filtering and rendering failures.
- Broken link detection
- Crawls campaign links and flags dead or broken destinations, a spam signal and a conversion killer in one.
- Blocklist exposure checks
- Surfaces blocklist issues connected to the send as part of the same 200-credit analysis.
Inbox Placement testing
A credit-metered prediction of where a send will land.- Cross-provider placement prediction
- Tests whether a message reaches the inbox or spam across major providers including Gmail, Yahoo, and AOL, at 200 credits per test.
- Pre-send snapshot workflow
- Designed as a check before a campaign rather than continuous monitoring; run it on demand and compare across sends.
Reporting, integrations, and account
The plumbing that keeps hygiene visible and connected to the sending stack.- Usage reports
- In-depth evaluation of list health over time plus analysis of uploads, integrations, and API activity.
- Native ESP integrations
- Direct connections to MailerLite, Mailchimp, ActiveCampaign, GetResponse, and ConvertKit sync lists in and verified results back out.
- Zapier and Make automation
- No-code connectors put verification inside broader automation flows without touching the API.
- Non-expiring credit wallet
- Credits persist indefinitely, so occasional senders are not forced onto a subscription clock.
- Free starter credits
- 10 free credits on signup let new users test verification with no card on file.
Use cases
4 documentedNewsletter operator on MailerLite
An older list has accumulated years of decay, bounce warnings are appearing, and the sender does not want a monthly deliverability bill for a quarterly problem.
A one-off credit purchase verifies the full list through the native integration, automated recommendations prune the hard bounces and quarantine catch-alls, and leftover credits sit in the wallet for the next cleanup.
E-commerce marketer collecting signups at checkout
Typo domains and disposable addresses pollute the list at the point of collection, quietly dragging bounce rates and provider reputation down.
The real-time API verifies each address at the form for a cent, keeping the junk out of the database entirely instead of paying to clean it out later.
Lifecycle marketer preparing a major campaign
A redesigned template with new copy is about to hit the full list, and the last redesign tanked open rates for reasons nobody diagnosed.
A $2 Email Insights run flags spam-trigger phrasing and two broken links, and a $2 Inbox Placement test confirms the fixed version lands in Gmail's inbox before the send commits.
Agency doing periodic list audits for clients
Half a dozen small clients each need an annual list cleaning and a placement sanity check, but none generates enough volume to justify per-client subscriptions.
One credit wallet serves every client's occasional verification and testing needs, and usage reports document the work for client billing.
Pricing
from $10 (1,000 credits, pay as you go)Pure pay-as-you-go credits: $0.01 per credit with a 1,000-credit minimum purchase, no subscription tiers, and credits that never expire. Verification costs 1 credit per address; Email Insights and Inbox Placement cost 200 credits per test.
| Plan | Price | Includes |
|---|---|---|
| Pay as you go | $0.01 per credit one-time purchases, 1,000-credit minimum |
No published subscription or bulk-discount tiers as of August 2026; the price per credit is flat regardless of volume. |
Billing notes
- The published model is strictly pay-as-you-go at a flat $0.01 per credit as of August 2026, with no quantity discounts listed; high-volume verifiers should ask about enterprise terms rather than assume a volume break.
- Refunds are only provided if MailerCheck terminates service without cause, so buy credits in modest batches.
- A 200-credit ($2) meter per Insights or Placement test is cheap for occasional checks but compounds for teams testing many variants or testing daily.
- The 10 free signup credits cover testing verification on a handful of addresses, not a placement or Insights run, which each need 200 credits.
Value assessment: For its core job, MailerCheck is close to unbeatable on friction: $10 in, a cent per address, nothing expiring, and no subscription guilt for the months you send nothing. That makes it the rational default for small and seasonal senders, and the $2 placement and content tests are honest conveniences at that scale. The flat rate cuts the other way at volume, where dedicated verifiers negotiate below a cent and testing-heavy teams outgrow the per-test meter; and because nothing here warms, monitors continuously, or parses DMARC, MailerCheck is the hygiene-and-spot-check layer of a deliverability stack, never the whole stack.
Strengths & limitations
Strengths
- Lowest-friction pricing in the category: $10 minimum, flat cent per verification, non-expiring credits, and 10 free credits with no card to start.
- Verification, content analysis, and placement testing in one credit wallet covers the pre-send checklist most marketers actually run.
- Real-time API verification at the signup form prevents list decay at the source rather than billing you to clean it later.
- Native integrations with the small-sender ESP stack (MailerLite, Mailchimp, ActiveCampaign, GetResponse, ConvertKit) plus Zapier and Make make round-trip list cleaning nearly frictionless.
- Institutional backing most micro-vendors here lack: built by the MailerLite team (founded 2010 in Vilnius), part of listed Polish email group Vercom S.A. since 2022, with a claimed 255,000+ users.
- Automated post-verification recommendations turn raw results into an actionable delete-and-segment plan for non-experts.
Limitations
- No warming, no continuous blacklist monitoring product, and no DMARC analytics; senders with reputation problems need other tools for remediation and deep diagnosis.
- Inbox Placement is a per-test prediction across major providers, shallower than GlockApps' seed panels with per-filter spam scoring and scheduled monitoring.
- Catch-all addresses are flagged, not conclusively resolved, which limits usefulness on enterprise B2B lists where catch-alls dominate.
- No published volume discounts; at a flat cent per check, million-address workloads price worse than negotiated rates at dedicated bulk verifiers.
- Company transparency is modest for the size of its parent: no published HQ, headcount, or leadership for MailerCheck itself, and no SOC 2 or equivalent attestation advertised.
- The 98 percent-plus delivery-rate claim, like all such figures in this niche, is self-reported and depends heavily on what senders do after verification.
Head-to-head comparisons
4 alternativesMailerCheck vs Allegrow
from $99/mo (Starter, 5,000 verifications)MailerCheck and Allegrow bracket the verification market. MailerCheck is the cent-per-check generalist for marketers: cheap, pay-as-you-go, flags catch-alls and moves on. Allegrow conclusively resolves catch-alls and gateway-protected enterprise addresses and enforces hygiene inside Outreach and Salesloft at a hundred times the budget. Consumer and newsletter lists take MailerCheck; enterprise B2B data quality takes Allegrow.
Full MailerCheck vs Allegrow comparisonMailerCheck vs GlockApps
from $59/mo (Essential, billed annually)Both test placement, but the centers of gravity differ: MailerCheck is a verifier with a $2 placement prediction attached, GlockApps is a testing-and-monitoring platform (70+ seed addresses, per-filter scoring, DMARC analytics, blacklist monitoring) with no verification. Occasional pre-send sanity checks favor MailerCheck's meter; a real measurement program favors GlockApps' subscription.
Full MailerCheck vs GlockApps comparisonMailerCheck vs MailStrike
from $29/moMailStrike approaches deliverability from the sending side, warming and repairing reputation with testing folded into the loop, while MailerCheck approaches it from the data side, cleaning lists and spot-checking content and placement with no warming at all. They complement rather than compete: MailStrike fixes how you send, MailerCheck fixes what you send to.
Full MailerCheck vs MailStrike comparisonMailerCheck vs Warmup Inbox
from $15/inbox/mo (Basic, billed annually at $180/yr)A clean remediation-versus-hygiene split: Warmup Inbox builds and maintains sender reputation through its warming network and monitors 100+ blacklists, but never checks whether your addresses are real; MailerCheck verifies every address for a cent but cannot lift a domain out of spam. Cold outbound programs generally need both jobs done, by one tool from each side.
Full MailerCheck vs Warmup Inbox comparisonImplementation & onboarding
- Setup time
- Minutes: sign up, use the 10 free credits, buy a credit pack, and upload a list or connect an ESP. API integration at a signup form is a small engineering task measured in hours.
- Learning curve
- Low. Verification verdicts and automated recommendations are written for marketers, not deliverability specialists; Insights and Placement reports are similarly plain.
- Onboarding
- Fully self-serve with documentation; no assigned onboarding.
- Migration notes
- Nothing to migrate: lists flow in from files or ESP integrations and verified results flow back out. Dropping the tool costs only the credit balance and historical usage reports, so switching verifiers is trivial.
Platform, API & security
- Platforms
- Web appREST API (verification, including real-time)
- API
- Real-time and bulk verification API metered on the same credit balance as the web app; no separate API subscription. Published documentation covers verification endpoints; Insights and Placement are app-driven.
- Compliance
- GDPR-aligned processes (EU-rooted organization)
- Data residency
- Not publicly specified.
- SSO
- Not advertised.
- Security notes
- Verification requires only the address data you submit; no mailbox credentials are connected for the core product, which keeps the standing-access risk profile lower than warming tools that hold OAuth or SMTP access.
Support & resources
- Channels
- Email supportHelp center
- Documentation
- Help documentation plus guides on verification categories, deliverability practice, and API usage.
- Community
- No dedicated community; MailerCheck leans on the broader MailerLite ecosystem's content and audience.
Company
- Founded
- 2019
- Headquarters
- Vilnius, Lithuania (MailerLite group; MailerCheck's own registered base is not separately published)
- Ownership
- Owned by Vercom S.A. (listed Polish email-infrastructure group) via its 2022 acquisition of MailerLite
- Employees
- Not disclosed (a product team within the MailerLite organization)
- Funding
- MailerLite was bootstrapped, then acquired by Vercom S.A. for $90M in 2022; MailerCheck raised no separate funding.
Timeline
- 2010MailerLite founded in Vilnius, Lithuania; a decade of ESP operations later supplies the deliverability data behind MailerCheck.
- 2019MailerCheck launches as MailerLite's standalone email verification product.
- 2022Vercom S.A., a listed Polish email-infrastructure group, acquires MailerLite (MailerCheck and MailerSend included) for $90M.
- 2023Email Insights and Inbox Placement extend the product from pure list verification into content and placement testing.
- 2026As of this review the product runs on flat pay-as-you-go pricing ($0.01 per credit, non-expiring) and claims 255,000+ users worldwide.
Integrations
- MailerLite
- Mailchimp
- ActiveCampaign
- GetResponse
- ConvertKit
- Zapier
- Make
- REST API (real-time and bulk verification)
Frequently asked questions
10 questionsWhat does MailerCheck do?
MailerCheck verifies email addresses, individually, in bulk, or in real time at signup via API, flagging invalid addresses, syntax errors, catch-alls, and other bounce risks. It also offers credit-metered Email Insights (spam words, broken links, code issues, blocklist exposure) and Inbox Placement tests predicting whether a send lands in the inbox or spam.
How much does MailerCheck cost?
It is pure pay-as-you-go: $0.01 per credit with a 1,000-credit ($10) minimum, and credits never expire. Verifying an address costs 1 credit; an Email Insights analysis or an Inbox Placement test costs 200 credits ($2) each. New accounts get 10 free credits with no card required.
Do MailerCheck credits expire?
No. Credits persist indefinitely, which is the product's key structural advantage for seasonal and occasional senders over subscription-based competitors. The tradeoff is a strict refund policy: refunds only apply if MailerCheck terminates service without cause.
Is MailerCheck part of MailerLite?
Yes, it was created by the MailerLite team, launched in 2019, and sits alongside MailerLite and MailerSend in the same product family. The whole group was acquired by Vercom S.A., a listed Polish email-infrastructure company, for $90M in 2022.
How accurate is MailerCheck's verification?
MailerCheck claims 98 percent-plus delivery rates for verified lists, in line with competitors' self-reported figures. Like all verifiers, it is most decisive on clear valids and invalids; catch-all domains are flagged as risks rather than conclusively resolved, so B2B lists heavy in catch-alls retain real uncertainty.
Does MailerCheck do email warm-up?
No. There is no warming network, and MailerCheck cannot build or repair sender reputation. Cold-email senders typically pair it (or a similar verifier) with a dedicated warmer like Warmup Inbox, Warmbox, or Mailivery.
What is Email Insights?
A 200-credit pre-send analysis of a campaign's content: it flags spam-trigger words, poorly formed HTML, broken links, and blocklist issues so problems get fixed before the send rather than diagnosed after it.
How does MailerCheck's Inbox Placement test work?
For 200 credits it predicts whether your email will reach the inbox or the spam folder across major providers such as Gmail, Yahoo, and AOL. It is a pre-send snapshot rather than continuous monitoring, and it is shallower than a dedicated seed-panel platform like GlockApps with per-filter scoring and DMARC analytics.
Can MailerCheck verify emails in real time?
Yes, the real-time API verifies addresses at the moment of collection, on signup forms or inside automations via Zapier and Make, drawing on the same credit balance as bulk verification. Blocking a bad address at the door costs the same cent as cleaning it later and saves the bounce.
Which tools does MailerCheck integrate with?
Native integrations cover MailerLite, Mailchimp, ActiveCampaign, GetResponse, and ConvertKit for round-trip list cleaning, plus Zapier and Make for no-code automation and a REST API for custom workflows.
Editorial verdict
MailerCheck wins on economics and honesty of scope. A cent per verification, a $10 entry, non-expiring credits, and $2 spot checks on content and placement make it the obvious hygiene layer for newsletter and lifecycle senders who refuse to carry another subscription, and the MailerLite pedigree gives it more institutional weight than most tools this cheap. But its scope is exactly what it says: it cleans lists and runs spot checks. It will not warm a domain, watch your blacklists overnight, parse DMARC, or resolve the catch-alls that dominate enterprise B2B data. Treat it as the cheapest reliable answer to the list-quality question, and buy the reputation and measurement layers, if you need them, elsewhere.
Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.