mailfloss

Name: mailfloss
Brand: mailfloss
Price: 2910000 USD

The verifier that repairs the typo instead of deleting your customer

mailfloss is an email verification service that runs on autopilot inside your email platform rather than as a file you upload, connecting over OAuth to forty ESPs and CRMs and then doing four jobs continuously: fixing misspelled addresses against more than 250 typo patterns, blocking bad signups in real time, sweeping every new subscriber daily, and re-verifying your existing list on a schedule to catch decay. It is bootstrapped, based in Canada, has been running since 2017, and starts at $29 a month for 10,000 credits with a seven-day free trial.

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Overview

mailfloss started as a founder's chore. Martin was exporting a list, running it through a verifier, re-importing the survivors, and then forgetting to do it again for a month. The job was important, tedious, and easy to skip, which is the exact shape of work software should eat. So the product was built to connect directly to the email platform and run in the background, and the company still measures success by how rarely you have to think about it.

The signature feature is typo repair, and it is a genuinely different commercial position rather than a nicety. When someone signs up as user@gmial.com, every other verifier marks the address invalid and deletes it, which quietly destroys a customer you already paid to acquire. mailfloss recognises the pattern across more than 250 typo variants and fixes the domain, keeping the subscriber. The vendor's own arithmetic is that around one in every 32 subscribers is lost this way, and it publishes a calculator that turns that into a customer-acquisition-cost figure. It is marketing, but the underlying point is correct: verification that only deletes is doing half the job.

Around that sit three more automations. Instafloss verifies each new signup at the moment it arrives, blocking bots, fakes, disposables, role accounts, and dead domains before they reach the list, with the vendor citing around 14 percent of signups blocked on a typical newsletter. Autofloss is the fallback for teams who cannot add a script to a form, sweeping the previous 24 hours of new subscribers each morning. Decay Protection re-verifies the whole existing list on a cadence you choose, anywhere from weekly to twice a year with monthly as the default, on the basis that roughly 22 percent of any list over two years old has rotted.

The tradeoffs are exactly what you would expect from a small, focused, bootstrapped product. There is no catch-all resolution, so B2B outbound teams do not belong here. Subscription plans require a supported ESP, and while forty platforms is a lot, if yours is missing you are pushed to prepaid credits and CSV uploads, which is precisely the workflow the product exists to abolish. And the credit allowances are small relative to bulk verifiers: $209 a month buys 125,000 credits, where a bulk vendor charges under $200 for a one-off clean of the same volume. You are paying for the automation, not for the checks.

Best for

Newsletter operators, ecommerce email marketers, and small businesses running a permission-based list inside a supported ESP, who want list hygiene to be a background process rather than a recurring manual chore, and who care about keeping mistyped subscribers rather than deleting them.

Not the right fit for

B2B outbound teams working accept-all domains, since mailfloss offers no catch-all resolution and is built around ESP-side list hygiene rather than cold list qualification.
Anyone whose email platform is not one of the forty supported, because the whole value is the native two-way connection and the fallback is exactly the CSV round trip the product exists to replace.
High-volume bulk cleaners, who will find $209 a month for 125,000 credits poor value against a one-off bulk clean of the same volume for under $200 at several competitors.
Teams that want a single deep verification of a static list and then nothing else, since the pricing and the product are both built around continuous operation.
Buyers who need audited certifications; mailfloss publishes GDPR compliance, a status page, and a privacy policy, and no SOC 2 or ISO report.

How it works

1
You start a seven-day free trial, which requires a card but does not charge until day eight, and connect an email platform over OAuth from the dashboard. There are no API keys to copy and no Zapier in the middle, and the vendor says most platforms connect in under thirty seconds.
2
Once connected, the integration is two-way. Removals, tags, and typo fixes are written straight back into the platform, so there is nothing to re-upload and nothing to reconcile. Every connection carries its own rules, so you can delete invalid addresses on one platform, merely tag them on another, and enable Typo Fixer only where you want it.
3
Four products then run continuously. Typo Fixer repairs misspelled domains at every stage. Instafloss verifies new signups the instant they arrive. Autofloss sweeps the last 24 hours of signups once a day for teams who cannot install a script. Decay Protection re-verifies the entire existing list on a cadence from weekly to every six months.
4
Custom keep and remove rules decide what happens to each category of result, and higher tiers add webhooks, a real-time API, auto-tagging after verification, and Zapier. If your platform is not among the forty supported, you buy prepaid non-expiring credits instead and upload a CSV, or use the extensions for Google Sheets, Airtable, and Zapier.

Feature breakdown

31 features in 5 modules

Typo Fixer

The feature the company was built around, and the one nobody else treats as a product.

More than 250 typo patterns: Recognises common misspellings across every major email domain, from gmial and gmai to hotmial and outlok, and repairs the address rather than marking it invalid.
Repair rather than delete: Where a conventional verifier removes a mistyped address and silently loses the subscriber you already paid to acquire, mailfloss keeps them by fixing the domain and writing the correction back to the platform.
Applied across every other product: Typo Fixer layers on top of Instafloss, Autofloss, and Decay Protection, so repairs happen at signup, in the daily sweep, and during scheduled re-verification alike.
Enabled per connection: Because each platform connection has its own settings, you can run Typo Fixer on a newsletter list and leave it off a transactional system where corrections would be inappropriate.
Quantified recovery: The vendor puts the loss at roughly one in 32 subscribers and publishes a calculator translating that into wasted customer acquisition cost, with more than 60 million typos fixed to date.

The autopilot stack

Four products covering the whole subscriber lifecycle.

Instafloss real-time verification: Verifies every new signup the moment it arrives, blocking bot and spam registrations, fakes, disposable addresses, role accounts, and dead domains before they reach your list. The vendor cites around 14 percent of signups blocked on a typical newsletter.
Autofloss daily sweep: For teams who cannot add a script to their forms, a daily job scans every subscriber added in the previous 24 hours and removes anything that failed validation, catching the same problems a day later.
Decay Protection: Periodically re-verifies your entire existing list on a cadence you set from weekly to every six months, monthly by default, removing addresses that have rotted since they joined. The vendor puts decay at around 22 percent of any list over two years old.
JavaScript form widget: A separate widget covers opt-in forms directly, for verification at the point of capture on pages outside the connected platform.
Custom keep and remove rules: You decide which result categories get deleted, tagged, or left alone, per connection, which matters because an aggressive default removal policy on a list you care about is a destructive operation.
Auto-tagging after verification: Subscribers can be tagged with their verification outcome inside the platform, so segmentation can use verification state without anything being deleted.
Spotless, in development: An announced extension beyond email that title-cases names, standardises phone numbers to E.164, and validates postal addresses, aiming at whole contact records rather than just the email field.

Verification checks

Twenty-plus checks per address, iterated on since 2017.

More than twenty checks per address: The vendor states each address runs through over twenty checks on global infrastructure, with more than a billion addresses verified to date.
Bot and spam signup blocking: Catches automated registrations at the point of capture, which on a public form is often the single largest source of list pollution.
Disposable address detection: Blocks throwaway providers used to claim discounts and trials, which are deliverable at signup and worthless within days.
Role account detection: Flags shared mailboxes such as info@ and support@, which are technically valid but rarely belong on a marketing list.
Dead domain detection: Removes addresses whose domains no longer resolve or accept mail, which is the largest single category of decay on an ageing list.
Bounce prevention framing: The product is measured on bounce rate rather than on classification accuracy, which is the right outcome metric for the marketing lists it serves.

Integrations

Forty platforms with real two-way connections, not a Zapier veneer.

One-click OAuth connection: Authorise from the dashboard with no API keys and no developer, disconnect at any time, and the vendor claims most platforms connect in under thirty seconds.
Two-way writeback: Removals, tags, and typo corrections are written back into the source platform, which is the difference between an integration and an export.
Forty supported platforms: Mailchimp, Klaviyo, HubSpot, ActiveCampaign, Kit, beehiiv, GoHighLevel, Braze, AWeber, Drip, MailerLite, Constant Contact, Brevo, Campaign Monitor, GetResponse, Ontraport, iContact, Sendlane, Moosend, Keap, Intercom, Customer.io, Iterable, Ghost, Emma, SendPulse, Benchmark, Mautic, MailUp, ActiveTrail, VerticalResponse, Gist, Wishpond, Campaigner, Autopilot, Encharge, ClickFunnels, DailyStory, Mailigen, and Remarkety.
Per-connection settings: Rules, cadences, and features are configured independently for each connected platform rather than globally, which matters for agencies and multi-brand operators.
Sheets, Airtable, and Zapier extensions: For platforms outside the supported forty, extensions cover spreadsheet and automation workflows without a native connector.
Real-time API and webhooks: Available on subscription plans for teams that want to call verification directly or react to results in their own systems.

Commercial terms

Small, honest, bootstrapped pricing with a volume selector inside each tier.

Three tiers with in-tier volume scaling: Lite at $29 a month from 10,000 credits, Business at $59 from 25,000, and Pro at $209 from 125,000, each with a dropdown that scales the included credits up to roughly half a million or more at a higher monthly price.
Platform connection limits define the tiers: Lite connects one platform, Business connects ten, and Pro connects unlimited platforms and adds priority human support and single sign-on.
Seven-day free trial: Every subscription plan starts with a seven-day trial. A card is required but nothing is charged until day eight.
Non-expiring prepaid credits: A one-time prepaid option covers bulk CSV verification with no subscription and credits that stay in the account until used, which is also the fallback if your platform is not supported.
Annual billing saves 17 percent: The standard annual discount, applied across the tiers.
Money-back guarantee: Published alongside the trial, though the specific terms are not detailed on the pricing page.
Deliberately low pricing: The company states it is customer-funded with no investors to satisfy, and treats keeping prices among the lowest in the industry as a stated principle rather than a promotion.

Use cases

4 documented

Ecommerce marketer on Klaviyo losing customers to typos

Paid acquisition costs $50 a customer, and every mistyped signup is quietly deleted by the verifier, wasting the acquisition spend without anybody noticing.

Typo Fixer repairs the addresses and keeps the subscribers, Instafloss blocks the bot signups that were inflating the Klaviyo bill, and both write back into Klaviyo automatically with no export.

Newsletter operator who never remembers to clean

List hygiene happens when a bounce spike forces it, which is always after the deliverability damage rather than before.

Autofloss sweeps yesterday's signups every morning and Decay Protection re-verifies the whole list monthly, so hygiene becomes a background process and the sender reputation stops sawtoothing.

Agency managing several client lists on different platforms

Each client runs a different ESP with different rules about whether bad addresses should be removed or merely flagged.

The Business plan connects ten platforms and Pro connects unlimited, each with its own keep and remove rules, cadence, and Typo Fixer setting, so one subscription covers a portfolio without a shared policy.

SaaS company with a public signup form under bot pressure

Automated registrations are polluting the user table and every downstream per-contact tool is charging for junk.

Instafloss verifies at the moment of signup and blocks bots, fakes, disposables, and dead domains, with the vendor citing around 14 percent of signups blocked on a typical form, and the real-time API covers anything outside the connected platform.

Pricing

from $29 per month for 10,000 credits, with a seven-day free trial

Monthly or annual subscriptions priced by verification credits per month, with each tier carrying a volume selector, plus a separate one-time prepaid credit option with credits that never expire for teams on unsupported platforms or doing a one-off bulk clean.

Plan	Price	Includes
Lite	$29 per month, from 10,000 credits	10,000 credits a month at $0.0029 each Volume selector scales to 20,000, 60,000, 110,000, 260,000, or 510,000 credits at higher monthly prices Connect 1 email platform Daily cleaning, decay removal, typo fixing, and custom rules Aimed at small businesses running a single list on a single platform.
Business	$59 per month, from 25,000 credits	25,000 credits a month at $0.00236 each Volume selector scales to 35,000, 75,000, 125,000, 275,000, or 525,000 credits Connect 10 email platforms Zapier, real-time API, webhooks, and auto-tagging The vendor's best-value tier and the natural choice for ecommerce marketers running more than one list.
Pro	$209 per month, from 125,000 credits	125,000 credits a month at $0.00167 each Volume selector scales to 135,000, 175,000, 225,000, 375,000, or 625,000 credits Connect unlimited email platforms Priority human support Single sign-on The only tier with SSO and unlimited platform connections, which is what makes it the agency tier.
Prepaid credits	One-time purchase credits never expire	For one-off bulk CSV verification with no subscription The fallback if your email platform is not among the supported forty Credits remain in the account until used No automation; this is manual upload and download Buying prepaid means giving up the autopilot behaviour that is the entire reason to choose mailfloss.

Billing notes

At the reference volumes, 10,000 credits a month costs $29 on Lite, or $0.0029 per address. Reaching 100,000 a month means either a higher Lite or Business volume step or the $209 Pro plan, which includes 125,000 credits at $0.00167 each. One million a month is above every published tier and requires a conversation or prepaid credits.
Those are recurring monthly prices, not one-off cleans, which is the correct comparison to make. A one-time clean of 100,000 addresses costs about $99 at MyEmailVerifier, $186 at EmailListVerify, and $185 at ListWise, so mailfloss at $209 a month only makes sense if you are actually verifying continuously.
Each tier carries a volume dropdown rather than a hard cap, so Lite can scale to 510,000 credits a month and Business to 525,000 at higher monthly prices. The tiers are really differentiated by platform connection limits, support level, and SSO rather than by volume.
Annual billing saves 17 percent across the plans.
Prepaid credits never expire, which makes them a reasonable safety net, but buying them means opting out of the automation the subscription exists to provide.
A card is required to start the seven-day trial and billing begins on day eight, so cancel deliberately rather than assuming a lapse.
The vendor does not publish whether unresolved or unknown results consume credits, which is the standard gap at this end of the market.

Value assessment: Judge mailfloss on labour and retention, not on price per address. Per credit it is unremarkable, around $0.0017 to $0.0029, which is more than MyEmailVerifier or Truelist charge for a straight bulk clean. What you are buying is that the clean actually happens, every day, inside the platform where your contacts already live, with removals and tags written back automatically, and that mistyped subscribers are repaired rather than deleted. For a marketing team, the recurring cost of forgetting to clean, plus the acquisition spend wasted on deleted typos, plausibly exceeds the subscription. Two conditions have to hold for that to be true: your platform must be among the supported forty, and your list must be permission-based rather than cold. If either fails, mailfloss is the wrong shape and a bulk verifier at a third of the price does the job you actually have.

Strengths & limitations

Strengths

Typo repair across more than 250 patterns is a genuine differentiator with a direct revenue argument, and no other verifier profiled here treats it as a product.
Forty native two-way OAuth integrations with per-connection rules, which turns list hygiene into a background process instead of a recurring CSV chore.
The four-product lifecycle coverage, signup-time blocking, next-day sweep, and scheduled decay re-verification, is more complete automation than any other verifier here offers.
Genuinely cheap entry at $29 a month, from a bootstrapped company that states low pricing as a principle rather than a promotion.
Custom keep and remove rules per connection, plus auto-tagging, so verification does not have to mean deletion on a list you care about.
Nine years of continuous operation, more than 5,000 teams, over a billion addresses verified, and more than 60 million typos fixed.
Customer-funded with no investors, which is the structural reason the pricing has stayed low and the product has stayed narrow.

Limitations

No catch-all resolution at all, which rules out B2B outbound work entirely.
Subscription plans require one of forty supported platforms, and the fallback for everyone else is prepaid credits and manual CSV uploads, which is the exact workflow the product exists to eliminate.
Poor value as a bulk cleaner: $209 a month for 125,000 credits against roughly $100 to $190 for a one-off clean of the same volume elsewhere.
No permanently free tier, and the seven-day trial requires a card, which is less generous than the daily free credits at MyEmailVerifier and Verifalia.
No published certifications beyond GDPR compliance, no trust centre, and no published data retention or residency commitments.
Very small team by the company's own description, which is charming for support quality and a real concentration risk for a system with write access to your subscriber database.
Automatic removal is destructive by design, so custom rules should be configured in tag-only mode and observed before letting the system delete anything.
Spotless, the contact-field cleaning extension, is announced but not shipped, so it should not factor into a buying decision.

Head-to-head comparisons

5 alternatives

mailfloss vs ListWise

from $0 to clean up to 1,000 addresses, then $45 for 10,000 prepaid or $44 per month

ListWise includes automatic typo fixing quietly as part of its clean, which is the one feature mailfloss built a company around. But ListWise is a file-in, file-out bulk service with no ESP integrations at all, where mailfloss connects natively to forty platforms and runs continuously. ListWise is the better one-off cleaner and considerably cheaper for a large list; mailfloss is the better ongoing process. A bulk list owner should take ListWise, a newsletter operator mailfloss.

Full mailfloss vs ListWise comparison

mailfloss vs Scrubby

from $47 per month for 6,000 credits, with 200 free credits on signup

Opposite ends of the same category. Scrubby is a B2B outbound instrument that will send real mail and wait 72 hours to resolve a catch-all address, at roughly $0.005 to $0.008 a credit. mailfloss is a marketing-list autopilot at $29 a month that will not touch a catch-all. A company running both a newsletter and a cold outbound motion could reasonably buy each for its own job and should not expect either to cover the other.

Full mailfloss vs Scrubby comparison

mailfloss vs Truelist

from $0 for 100 validations, then $1.40 per 1,000 credits pay-as-you-go, or $799 per month unlimited

Truelist is cheaper per address, resolves catch-alls through a three-credit enhanced pass, and offers Recurring Validation on a schedule, but its integration list is short and it is fundamentally an engine you point at a list. mailfloss has forty native two-way connections and real-time signup blocking. Take Truelist for B2B lists and developer control; take mailfloss for an ESP-resident marketing list that should clean itself.

Full mailfloss vs Truelist comparison

mailfloss vs Emailable

from $38 for 5,000 credits pay-as-you-go, or $32.30 per month on subscription

Emailable is the closest thing to a direct competitor: a polished, marketing-friendly verifier with ESP integrations and a policy of not charging for unknown results. mailfloss goes further on automation with its four-product autopilot stack and much further on typo repair, while Emailable is stronger as a general-purpose verifier with clearer credit terms. Choose Emailable if you want a good verifier with integrations; choose mailfloss if you want to stop thinking about the job entirely.

Full mailfloss vs Emailable comparison

mailfloss vs ZeroBounce

from $0 for 100 credits a month, then $39 for 2,000 pay-as-you-go credits or $99 a month for ZeroBounce ONE

ZeroBounce is the full deliverability suite with warmup, inbox placement, blacklist monitoring, SOC 2 Type 2, and ISO 27001, at several times the price. mailfloss does one narrow thing continuously and cheaply. For an enterprise marketing team with a procurement process, ZeroBounce; for a small business that needs the list cleaned without anyone owning the task, mailfloss at $29 a month is a far better fit.

Full mailfloss vs ZeroBounce comparison

Implementation & onboarding

Setup time: Under a minute for the connection itself. OAuth from the dashboard, no API keys, no developer, and the vendor claims most platforms connect in under thirty seconds. The configuration that actually matters, deciding what gets deleted and what gets tagged, deserves rather longer.
Learning curve: Low. The four products map to obvious moments in a subscriber's life, and the settings are per connection rather than global. The only real thinking is around removal policy, because the system acts on your live list without asking.
Onboarding: Entirely self-serve. Every plan starts with a seven-day trial from the website, and support is human and direct given the company's size, with priority support reserved for Pro.
Migration notes: Nothing to migrate technically, but there is one important sequencing rule: configure custom rules in tag-only mode first and watch a full cycle before enabling automatic removal, because deletions are written straight back into your live ESP and are not easily undone. If your platform is not among the supported forty, do not buy a subscription at all, because you would be paying for automation you cannot use.

Platform, API & security

Platforms: Web dashboardNative OAuth integrations with 40 ESPs and CRMsReal-time APIWebhooksJavaScript form widgetGoogle Sheets, Airtable, and Zapier extensions
API: A real-time API and webhooks are available on subscription plans for verification outside the connected platform, alongside the native integrations which are the primary interface. mailfloss publishes developer docs and a status page. Public rate limits and latency figures are not published, and the product is designed around continuous background operation rather than high-throughput synchronous calls.
Compliance: GDPR compliance (vendor stated)OAuth-based platform authorisation rather than stored API keys
Data residency: Not published. The company is based in Canada and describes its verification infrastructure as global.
SSO: Single sign-on is available on the Pro tier.
Security notes: Integrations are authorised over OAuth rather than by handing over API keys, and can be disconnected at any time from the dashboard, which is a better security posture than the key-pasting most competitors require. The important risk to weigh is not confidentiality but authority: mailfloss holds write access to your subscriber database and will delete records according to your rules, so those rules deserve the same review you would give a database migration.

Support & resources

Channels: Email support on all plansPriority human support on ProHelp centre
Documentation: Help centre, developer docs, a changelog, and a public system status page, plus comparison and review pages.
Community: No user forum. The company is small enough that support is direct rather than tiered.

Company

Founded: 2017
Headquarters: Canada
Ownership: Bootstrapped and customer-funded; mailfloss, Inc.
Founders: Martin
Employees: Very small; the company describes a team you could fit at one table
Funding: No outside funding. The company states it is customer-funded with no investors.

Timeline

2017mailfloss is founded in Canada by Martin, after a recurring manual routine of exporting a list, verifying it, and re-importing the survivors proved too easy to forget.
2018Typo Fixer ships as the first product, recovering subscribers that other verifiers were silently deleting, and becomes the company's defining feature.
2020Instafloss and Autofloss add real-time signup verification and a daily sweep, turning the tool from a cleaner into an autopilot.
2023Decay Protection extends coverage to existing lists with configurable re-verification cadences from weekly to twice a year.
2026Supports 40 native two-way platform integrations, reports more than 5,000 teams and over a billion addresses verified with 60 million typos fixed, and announces Spotless for cleaning non-email contact fields.

Integrations

Mailchimp
Klaviyo
HubSpot
ActiveCampaign
Kit
beehiiv
GoHighLevel
Braze
AWeber
Drip
MailerLite
Constant Contact
Brevo
Campaign Monitor
GetResponse
Ontraport
Keap
Intercom
Customer.io
Iterable
Ghost
Sendlane
Moosend
Encharge
ClickFunnels
Mautic
Zapier, Google Sheets, and Airtable extensions
Real-time API and webhooks

Frequently asked questions

10 questions

What is mailfloss?

mailfloss is an email verification service that runs automatically inside your email platform rather than as a file you upload. It connects over OAuth to forty ESPs and CRMs and then fixes typos, blocks bad signups in real time, sweeps new subscribers daily, and re-verifies your existing list on a schedule, writing removals, tags, and corrections back into the platform automatically.

How much does mailfloss cost?

Lite is $29 a month from 10,000 credits and connects one platform, Business is $59 from 25,000 credits and connects ten, and Pro is $209 from 125,000 credits with unlimited connections, priority support, and single sign-on. Each tier has a volume selector scaling up past half a million credits a month at higher prices. Annual billing saves 17 percent, and prepaid non-expiring credits are available for one-off bulk work.

What is the Typo Fixer and why does it matter?

It recognises more than 250 common misspelling patterns and repairs the address instead of deleting it. When someone signs up as user@gmial.com, every other verifier marks that invalid and removes a customer you already paid to acquire. mailfloss fixes the domain and keeps them. The vendor estimates roughly one in 32 subscribers is lost this way and publishes a calculator converting that into wasted acquisition spend.

How does mailfloss handle catch-all and accept-all addresses?

It does not resolve them. mailfloss is built for permission-based marketing lists inside an ESP, where catch-all domains are a small minority, rather than for cold B2B lists where they can be a third of the file. If your problem is a large accept-all bucket, Truelist, Scrubby, or BounceBan attack it directly and mailfloss does not.

Can mailfloss clean my list automatically on a schedule?

That is the entire product. Instafloss verifies each new signup as it arrives, Autofloss sweeps the previous 24 hours of signups every morning, and Decay Protection re-verifies your whole existing list on a cadence you choose from weekly to every six months, monthly by default. All three run continuously without anyone remembering to do anything, and all three write back into the connected platform.

Which email platforms does mailfloss support?

Forty, connected in one click over OAuth with two-way writeback, including Mailchimp, Klaviyo, HubSpot, ActiveCampaign, Kit, beehiiv, GoHighLevel, Braze, AWeber, Drip, MailerLite, Constant Contact, Brevo, Campaign Monitor, GetResponse, Keap, Intercom, Customer.io, Iterable, Ghost, and Mautic. If yours is not supported, you buy prepaid credits and upload a CSV instead, or use the Sheets, Airtable, and Zapier extensions.

Do mailfloss credits expire?

Subscription credits are a monthly allowance and the vendor does not publish a rollover policy, so treat them as use-it-or-lose-it within the month. Prepaid credits, which are the one-time option for bulk CSV work, do not expire and stay in your account until used. Note that buying prepaid means giving up the automation that is the reason to choose mailfloss in the first place.

Is there a free trial or free plan?

There is a seven-day free trial on every subscription plan, plus a money-back guarantee. A credit card is required to start the trial and billing begins on day eight, so cancel deliberately rather than letting it lapse. There is no permanently free tier, which is less generous than the daily free credits offered by MyEmailVerifier and Verifalia.

Is mailfloss safe to give write access to my subscriber list?

Connections are authorised over OAuth rather than by pasting API keys, and can be revoked from the dashboard at any time, which is a better posture than most competitors require. The real consideration is authority rather than confidentiality: mailfloss will delete records from your live list according to your rules. Configure custom rules in tag-only mode first, watch a full cycle, and only then enable automatic removal.

Who should not use mailfloss?

B2B outbound teams, because there is no catch-all resolution. Anyone whose platform is not among the supported forty, since the fallback is the CSV round trip the product exists to abolish. High-volume bulk cleaners, who will pay $209 a month for volume a competitor cleans once for under $200. And buyers who need audited certifications, which mailfloss does not publish.

Editorial verdict

mailfloss solves a different problem from every other verifier in this category, and it solves it well. The others answer the question is this address valid. mailfloss answers the question why is nobody cleaning this list, and its answer is to connect natively to forty platforms, run four automations continuously across the whole subscriber lifecycle, and write every removal, tag, and typo correction straight back where your contacts already live. The Typo Fixer alone is a defensible reason to buy it, because repairing a mistyped address keeps a customer you paid to acquire and every competitor simply deletes them. It is cheap, it is bootstrapped, and it has been doing this since 2017. The boundaries are clear and worth respecting: no catch-all resolution, so B2B outbound teams should look elsewhere entirely, and no value as a bulk cleaner, since $209 a month buys volume that a one-off competitor cleans for less. If you run a permission-based list inside a supported ESP and list hygiene is nobody's actual job, this is the right purchase and $29 a month is not a serious sum.

Written by the SaaSTracker editorial team. Awards, when shown, are judged against the published criteria in our methodology.