AT Valid vs Kickbox: An Honest Comparison
Last updated: September 2026
AT Valid runs an 11-step, 20+ check email validation engine — graded catch-all confidence, a toxicity score, website/domain analysis, a List Quality Report on every job, and an encrypted cache that revalidates for free. Kickbox is a respected, deliverability-first verification service. This page compares both on verifiable facts, with sources and dates, so you can pick the right platform for your team.
TL;DR verdict
AT Valid is built to be the most complete validation platform in this comparison: a published 99.5% accuracy across an 11-step engine with 20+ checks per address, including website and domain analysis, a graded catch-all confidence score (0–10), a toxicity score (0–5), a List Quality Report with a projected bounce rate on every bulk job, recurring list and blacklist/RBL monitors included from the GROWTH plan, and a 0-credit encrypted result cache. Every account starts with 200 free credits that never expire, with published pricing as low as $0.0027 per email at volume. Kickbox, for its part, has built a genuine deliverability-first reputation — a trademarked Sendex™ quality score, a public refusal to work with purchased lists, and a broader suite of deliverability services around a sending program (per kickbox.com) — which is a fair reason to consider it if that broader service is what you need. But for validation depth, list-health reporting and value per credit, AT Valid is the stronger platform.
About Kickbox
Kickbox is a US-based email verification company built by veterans of the email industry, with a deliverability-first positioning — verification is one part of a broader mission to help senders reach the inbox. Its best-known feature is the trademarked Sendex™ Score, a proprietary 0–1 quality metric (per kickbox.com), and the company publicly refuses to work with purchased or non-consensual lists, a stance we consider correct. According to its published billing policy (September 2026), Kickbox only charges credits for definitive results — risky or unknown outcomes are free.
About AT Valid
AT Valid runs AT Valid Score, an 11-step validation pipeline with 20+ checks per address: RFC 5322 syntax plus provider-specific username rules, full DNS/MX/SPF/DMARC/DKIM analysis, real SMTP mailbox verification with multi-pass greylist retry, website and domain analysis (parked, for-sale, monetized domains), a graded catch-all confidence score (0–10), a toxicity score (0–5), and DNSBL/Spamhaus checks — resulting in a published 99.5% accuracy, a 0–100 confidence score, a letter grade, and a plain-language reason for every address.
Every bulk job also generates a List Quality Report (health grade, projected bounce rate before and after cleaning, segments, top issues and recommendations), and an encrypted result cache reuses recent validations at 0 credits. The platform adds recurring list monitors and blacklist/RBL monitoring from the GROWTH plan, Have I Been Pwned breach intelligence (Enterprise), a free single-address validator, a real-time widget (v2.1), a REST API with public/secret keys, native integrations (Salesforce, HubSpot, RD Station, Mailchimp, Pipedrive, Zapier, webhooks), and a verifiable public CO₂ certificate. The entire platform runs in five languages — English, Portuguese, Spanish, Chinese and German — and is designed with LGPD and GDPR requirements in mind.
Feature comparison you can verify
Every Kickbox claim below comes from Kickbox’s published materials or third-party reviews of them, as of September 2026. Where something is not published, we say so instead of guessing.
| Feature | AT Valid | Kickbox |
|---|---|---|
| Published accuracy | 99.5% across 20+ checks | Not publicly disclosed |
| Website & domain analysis | Yes — flags parked, for-sale, redirecting or monetized domains | Not publicly documented |
| Catch-all confidence grading | 0–10 score (real name, corporate gateway, domain maturity) | Not publicly documented |
| Toxicity score | 0–5 index (spam-trap & risk patterns) | Not publicly documented |
| Quality score model | 0–100 confidence + toxicity (0–5) + catch-all confidence (0–10) | Sendex quality score (per kickbox.com) |
| List Quality Report | Health grade A–F, projected bounce rate before/after cleaning, segments, top issues | Not publicly documented |
| Recurring list monitors | Included from the GROWTH plan (weekly/bi-weekly/monthly, delta + webhook) | Not publicly documented |
| Blacklist/RBL monitors | Included — domains & IPs, alerts + history | Not publicly documented |
| 0-credit result reuse | Encrypted cache reuses recent results (30/90 days) at 0 credits | Not publicly documented |
| Multi-pass greylist retry | Up to 3 passes (Enterprise), no extra credit | Not publicly documented |
| Real-time widget | v2.1 — sub-status messages, per-key + per-IP anti-flood | Not publicly documented |
| Free single-address validator | Yes — no signup, 10 checks/day | Not publicly documented |
| Breach intelligence (HIBP) | Included (Enterprise) | Not publicly documented |
| Provider-specific username rules | Yes (e.g. Gmail 6–30 characters) | Not publicly documented |
| Free credits on signup | 200 credits, no credit card | 100 credits (published free trial) |
| Credit expiration | Never expire | Expire after 12 months (published terms) |
| Platform interface languages | 5 (EN, PT-BR, ES, ZH-CN, DE) | English |
| Native RD Station integration | Yes | Not publicly listed (Sept 2026) |
| CRM and marketing integrations | Salesforce, HubSpot, Mailchimp, Pipedrive, Zapier, REST API, webhooks | Published integrations directory |
| Verifiable CO₂-avoided certificate (ESG) | Yes — public certificate | No comparable feature publicly listed |
| LATAM presence | Brazilian company, PT-BR/ES support | US-based |
| Deliverability tools beyond verification | Blacklist/RBL monitors included in the platform | Yes — broader deliverability suite |
| Billing for risky/unknown results | 1 credit per verification | Definitive results only (published policy) |
Kickbox details based on Kickbox’s published pricing, trial and policies as reported in September 2026. Features and terms change — always confirm current details on kickbox.com.
Six differences that actually matter
Website & domain analysis
AT Valid checks the domain’s website itself — flagging parked, for-sale, redirecting or ad-monetized domains, a signal we haven’t seen published by Kickbox or other validators.
Graded catch-all confidence + toxicity
A catch-all domain gets a 0–10 confidence score instead of a blind “unknown” (real name, corporate gateway, domain maturity), and every address gets a separate 0–5 toxicity score for spam-trap and risk patterns.
Quality Report + recurring monitors
Every bulk job returns a health grade, a projected bounce rate before and after cleaning, and prioritized issues. From the GROWTH plan, recurring monitors and blacklist/RBL monitoring keep re-checking the same list and your sending domains automatically.
0-credit reuse + multi-pass retries
An encrypted result cache reuses a recent validation at 0 credits — 30 days for valid/not-found, 90 days for disposable/dead-domain/typo — and greylisted addresses get up to 3 free retry passes instead of a fresh charge.
Breach checks and an ESG certificate
Have I Been Pwned intelligence (Enterprise) adds a breach signal, and every cleaning job can issue a public, verifiable CO₂-avoided certificate — a combination we haven’t seen from Kickbox.
Lower price, credits that never expire
AT Valid’s published tiers reach $0.0027 per email at 100k, subscriptions cut a further 20%, and cache hits on repeat validations cost 0 credits. AT Valid credits never expire; Kickbox’s published terms (September 2026) have credits expiring after 12 months.
When Kickbox may be better
- You want deliverability tooling and expertise beyond list verification — Kickbox positions itself as a deliverability company, not only a validator (per kickbox.com).
- You rely on the Sendex™ 0–1 score and prefer a billing model where risky and unknown results consume no credits (Kickbox’s published policy, September 2026).
When AT Valid is better
- You want deeper per-address signal: a graded catch-all confidence score (0–10), a toxicity score (0–5), and website/domain analysis — none of which we’ve seen published by Kickbox.
- You send in bulk and want a List Quality Report with a projected bounce rate, plus recurring list and blacklist/RBL monitors included from the GROWTH plan.
- You don’t want to pay twice: an encrypted cache reuses recent results at 0 credits, and greylisted addresses get up to 3 free retry passes.
- You need Brazil/LATAM-specific reach: native RD Station integration, and a platform in 5 languages including PT-BR and ES.
- You want 200 free credits that never expire, with published pricing as low as $0.0027/email at 100k and a further 20% off on subscriptions.
- You need ESG or breach evidence: a verifiable public CO₂-avoided certificate on every job, and Have I Been Pwned checks on Enterprise.
- You want per-check transparency from 20+ verification checks with a published 99.5% accuracy.
Pricing, side by side (September 2026)
AT Valid
Never expiresKickbox
At 100,000 verifications, the published difference is $269 (AT Valid) versus $800 (Kickbox, as reported September 2026). AT Valid subscriptions cut a further 20% off these tiers, and the encrypted result cache means re-validating the same list within the cache window (30–90 days) costs 0 credits. Kickbox’s model has an advantage of its own: by its published policy, only definitive results consume credits. Weigh all of this against your list quality.
Switching from Kickbox in 3 steps
Export your data
Download your lists and past verification results from Kickbox or your ESP/CRM as CSV. Nothing locks you in — both platforms work with plain files.
Run a free side-by-side test
Create an AT Valid account (200 free credits, no card) and run a sample of the same file through bulk verification. Compare the verdicts address by address.
Swap the endpoint
Point your signup forms at the AT Valid REST API, or connect Salesforce, HubSpot, Mailchimp, RD Station, Pipedrive or Zapier. Keep your existing suppression rules.
Frequently asked questions
Is AT Valid a good Kickbox alternative?
Yes — if you want a validation platform with 200 free credits that never expire, a graded catch-all confidence score, a toxicity score on every address, a List Quality Report on every bulk job, native RD Station integration and a verifiable CO2-avoided certificate. Kickbox remains a strong choice for teams that want deliverability tooling and services around their sending program. Both companies share a firm anti-spam, permission-based ethos.
How many free credits do AT Valid and Kickbox offer?
AT Valid gives every new account 200 free verification credits with no credit card required, and they never expire. According to Kickbox’s published free trial (September 2026), new Kickbox accounts receive 100 free verification credits. Always confirm current offers on each provider’s website.
Do verification credits expire on AT Valid or Kickbox?
AT Valid credits never expire — you can buy a block of credits and use them whenever you need. According to Kickbox’s published terms as reported in September 2026, Kickbox credits expire after 12 months. Confirm the current policy on kickbox.com before purchasing.
Can I use AT Valid to clean a purchased email list?
AT Valid is built for permission-based email programs. Validation removes invalid and risky addresses, but it does not create consent — sending to purchased lists damages sender reputation and can violate laws like LGPD, GDPR and CAN-SPAM. Kickbox takes a similar public stance against purchased lists, and we consider that stance correct.
Is AT Valid compliant with LGPD and GDPR?
AT Valid is built by a Brazilian company and the platform is designed with LGPD and GDPR requirements in mind, including data minimization and secure processing. For details about how each provider handles data, review the published privacy documentation of AT Valid and Kickbox.
What does AT Valid check that Kickbox doesn’t publish?
AT Valid publishes several checks we haven’t seen documented on kickbox.com: website and domain analysis (parked, for-sale, redirecting or monetized domains), a graded catch-all confidence score (0–10) instead of a blind “unknown”, a 0–5 toxicity score on every address, and a full List Quality Report with a projected bounce rate on every bulk job. We can’t compare these directly because Kickbox doesn’t publish equivalents — if that changes, we’ll update this page.
Do I pay twice to re-validate the same list?
No. AT Valid’s encrypted result cache reuses a recent validation at 0 credits — 30 days for valid or not-found addresses, 90 days for disposable, dead-domain or typo results — and greylisted addresses get up to 3 free retry passes instead of a fresh charge. You only pay again once the cache window has passed or the result has changed.
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