Mailsurity vs BounceZero: Disposable Email Detection APIs Compared
BounceZero runs its own multi-signal pipeline for disposable detection, not just a static list. The real differences are in team controls, bulk scale, and how actionable the response is — not raw detection sophistication.
Quick take
BounceZero
A pay-as-you-go email verification API with a genuine multi-layer disposable-detection pipeline and large bulk-CSV limits. Confirm current details on bouncezero.io.
Mailsurity
500 free credits, no card required, plus per-team allow/deny rules and a risk-score decision API most disposable checkers don't publish. 99.4% accuracy at <100ms p99.
Pricing
BounceZero is pay-as-you-go with no subscription (verified September 2026). Check bouncezero.io/pricing for current rates. Figures below for Mailsurity are its live current prices, not estimates.
BounceZero
100 free credits every month, no card required
Pay-as-you-go, from $0.003/check at the entry tier ($6 for 2,000 credits) down to $0.0022/check at 1,000,000 credits; credits never expire, no subscription
≈ $3.00 per 1,000 checks at entry tier*
Mailsurity
500 free credits at signup, no card required
$5/mo on Starter ≈ $1.00 per 1,000 checks*
Starter
$5 / month
5,000 checks / month
Growth
$19 / month
25,000 checks / month
Scale
$59 / month
100,000 checks / month
* Cost-per-1,000 assumes the full monthly credit allotment gets used. Unused Mailsurity credits don't roll over, so the effective rate is higher below full utilization. BounceZero credits never expire, so its effective rate doesn't carry the same caveat.
Prices shown are Mailsurity's current live plans (see /pricing for the full breakdown, including annual billing). BounceZero figures reflect only what our own research verified against bouncezero.io/pricing in September 2026. Confirm current details before deciding, since vendor pricing can change.
Feature breakdown
Free tier
Mailsurity: 500 free credits at signup, no card required (one-time grant)
BounceZero: 100 free credits every month, no card required (recurring)
Latency & auth
Mailsurity: Yes, <100ms p99, bearer-token auth
BounceZero: Yes, REST API with X-API-Key header auth, under 500ms response
Detection method
Mailsurity: 5-layer cascade: per-team rules -> static legit-list -> 220k+ domain list -> cached AI verdict -> live heuristics/LLM for gray-zone domains
BounceZero: 4-layer pipeline: match against 800+ known providers (weekly refresh) -> domain-age analysis -> DNS fingerprinting (shared hosting / wildcard MX) -> ML pattern recognition for undiscovered providers
Per-team allow/deny rules
Mailsurity: Yes, per-team rules override the cascade before any other layer runs
BounceZero: Not published
Bulk CSV checking
Mailsurity: Dashboard CSV upload, capped at 100 unique domains per job, runs inline
BounceZero: CSV upload up to 1,000,000 addresses, with webhook support for async results
Decision transparency & calibration
Mailsurity: 0-100 risk score plus a resolved ALLOW/VERIFY/BLOCK decision (POST /api/assess), an outcome-feedback loop to calibrate scoring (POST /api/feedback), and the full cascade documented publicly
BounceZero: Response includes a numeric score field, but no published decision thresholds, outcome-feedback mechanism, or public methodology page beyond marketing claims
Where BounceZero's column says a capability “isn't published,” that reflects the limits of our own research, not a claim that BounceZero lacks it. Confirm specifics on bouncezero.io.
Integration: no SDK required
The entire Mailsurity integration is one authenticated POST with plain fetch. No client library required.
curl -X POST https://mailsurity.com/api/check-email \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"email": "user@mailinator.com"}'Want a risk score and a resolved decision instead of a boolean? See the decision API reference . Full request/response schema for the boolean endpoint, error codes, and code samples in eight languages: see the API reference.
Why a published detection methodology matters
BounceZero describes its pipeline in marketing terms (“65+ signals,” “4-stage pipeline”) without a public page laying out exactly how each layer works or how they weight against each other. Mailsurity publishes its full 5-layer detection cascade in detail: per-team rules, a curated legit-list, a 220k+ domain list, a cached AI verdict layer, and live heuristics with an LLM fallback for gray-zone domains, in that precedence order. If you're debugging why a specific domain got flagged, that transparency is the difference between reading a doc and filing a support ticket.
Which one should you use?
Pick BounceZero if…
You need very large bulk-verification jobs (up to a million addresses per upload) or prefer pay-as-you-go credits that never expire over a monthly subscription.
Pick Mailsurity if…
You want per-team allow/deny rules, a risk-score decision API with team-tunable thresholds, an outcome-feedback calibration loop, and a publicly documented detection cascade.
Why teams pick Mailsurity for disposable-specific detection
Per-team allow/deny rules
Override the cascade for your own trusted or blocked domains, evaluated before any other layer.
A decision, not just a boolean
A 0-100 risk score and ALLOW/VERIFY/BLOCK decision, calibrated over time against outcomes you report back.
Fast enough for the signup path
<100ms p99, so it runs inline on signup without slowing anyone down.
FAQ
Is BounceZero's 99.8% accuracy claim specific to disposable email detection?
No. BounceZero's own pricing page clarifies that the “up to 99.8%” figure is general platform accuracy for SMTP-verifiable addresses across their whole product, not a number stated specifically for disposable detection. Mailsurity's 99.4% figure, by contrast, is specifically its disposable/legitimate classification accuracy. The two numbers aren't measuring the same thing, so they shouldn't be compared directly.
Does BounceZero catch brand-new disposable domains before they land on a list?
BounceZero publishes a 4-layer pipeline that includes domain-age analysis, DNS fingerprinting, and an ML model it says flags providers “even if not yet in our database” — a claim genuinely comparable to Mailsurity's own AI fallback and MX-cluster reputation. Unlike DeBounce, BounceZero's API requires an X-API-Key header, so there's no public endpoint to independently test the way we live-tested DeBounce's free lookup. Take BounceZero's claim at face value pending your own verification, and see Mailsurity's own published 5-layer detection cascade for exactly how ours works.
Does BounceZero support per-team allow/deny rules or a risk-score decision API?
Not that we could find published anywhere on bouncezero.io. Its API response includes a numeric score field, but no documented decision thresholds or outcome-feedback mechanism. Mailsurity's decision API returns a 0-100 risk score plus a resolved ALLOW/VERIFY/BLOCK decision with team-tunable thresholds, and a companion feedback endpoint to calibrate scoring against real outcomes over time.
What does BounceZero's paid pricing look like at scale?
Pay-as-you-go with no subscription: about $0.003 per check at the entry tier (≈ $3.00 per 1,000), scaling down to $0.0022 per check at their largest tier (1,000,000 credits), per bouncezero.io/pricing (verified September 2026). Credits never expire, and unused credits are refundable within 30 days. Mailsurity's pricing is live on this page, pulled straight from our current plans (see the pricing section above) — subscription-based, with no metered pay-per-check tier.
Want the request/response details? The API reference covers authentication, the check-email endpoint, and code samples in eight languages.
How many disposable signups get through your forms
Paste your signup emails or domains and get an instant count: no signup, no card. Then start free on Mailsurity with 500 credits to try the full detection cascade yourself.