Kickbox vs mailboxlayer (2026): which should you pick?
As of Nov 12, 2026, Kickbox grades higher than mailboxlayer: 2.4 against 1.8 out of 4.0.
Checked Oct 18, 2026 and Nov 12, 2026 · graded Oct 18, 2026 and Nov 12, 2026 by ToolGPA
Kickbox grades higher on ease of use and platforms. They get the same grade on value for money, the free plan and features.
Price, platforms and features side by side. The table says where each price was read and when.
Kickbox
Pay-as-you-go email verification with an optional threat score
mailboxlayer
Email validation API that returns a JSON quality score
Which one is for you
Pick Kickbox if
- Fits if you check sign-ups in real time and want a sandbox to test against
- Works for teams on Braze, Iterable or Klaviyo who want checks built in
Look elsewhere if
- Pricey if you clean big lists, as a million checks cost $2,999
- Not for you if you need warm-up, placement tests or DMARC tools as well
- Watch out: Threat Score costs one more credit when it finds a signal, which can double the price of an address
- Tight if you want a monthly plan, as only one-off packs are listed
- Tight if you want to try it on a real list, as only the first 100 checks are free
Pick mailboxlayer if
- Fits if you are a developer who wants to check addresses at sign-up
- Works for side projects that stay under 100 requests a month
Look elsewhere if
- Not for you if you want to upload a list, because there is only an API
- Tight if you stay free, with 100 non-commercial requests
- Pricey if you want bulk: it starts at $74.99 a month
- Watch out: the homepage text mentions 1,000 free requests and $9.99 plans that the pricing page does not show
- Watch out: every address counts as one request
How we grade them
| 2.4GPAKickboxFair | 1.8GPAmailboxlayerWeak | |
|---|---|---|
| Value for money | C$70 for a one-off pack of 10,000. Among its listed rivals only ZeroBounce (about $129) costs more; NeverBounce is $50, Bouncer and Emailable $60 and DeBounce $25. Unknown results are refunded, and Threat Score costs one more credit only when it finds something. | CBasic is $14.99 a month for 5,000 requests, between the $10 cheaper quarter and the $17.99 middle. Professional Plus is $74.99 and Enterprise Plus $249.99, all billed monthly with yearly at a discount. |
| Free plan and trial | CNo free plan, but the first 100 checks are free. Enough to see what the results look like, not to clean a real list. | CFree is 100 API requests, non-commercial, with no support and no catch-all detection. Commercial use needs Basic. |
| Features | CIt does the checking job fully: bulk lists, a real-time API with a sandbox, a free check for disposable domains and an optional Threat Score. That's a smaller job, though: no warm-up, placement tests or DMARC tools. | CSyntax, SMTP, disposable and role checks with a score. No list upload exists, and catch-all detection and bulk need paid plans. |
| Ease of use | BNo App Store rating on record, but nothing to set up: upload a list and it comes back sorted by deliverability. Kickbox says 100,000 addresses take about an hour. | DNo store rating on record. It is an API only, so you need code to use it. |
| Platforms and integrations | BWeb and an API, with Mailchimp, Klaviyo, HubSpot, Braze, Iterable, SendGrid and Salesforce, and more through Zapier. No phone or desktop app. | CWeb API only. No apps and no integrations are listed. |
| Best for | checking sign-ups as they happen | an email check API for developers |
The GPA is the average of the five grades: an A is 4 points, an F is none. The full reasons are on each tool's page: Kickbox and mailboxlayer. How we grade
Where they differ
At a glance
| Kickbox | mailboxlayer | |
|---|---|---|
| Pricing | Free trial | Free plan |
| Starts at | $5 one-time for 500 verifications | $14.99 per month for 5,000 requests |
| Free plan | None | 100 API requests, for non-commercial use only. |
| Free trial | The first 100 verifications are free | None listed |
| Web | ||
| Made by | J2 Martech Corp | APILayer |
| Price read from | kickbox.com | mailboxlayer.com |
| Checked | Oct 18, 2026 | Nov 12, 2026 |
Worth knowing
Kickbox
- Only pay-as-you-go packs are listed; there is no monthly plan on the pricing page.
- Kickbox verifies addresses only; it has no warm-up, inbox placement testing or DMARC tools.
- Threat Score can double the cost per address when it finds a signal.
mailboxlayer
- An API only: there is no list upload or bulk cleaning page, and the bulk endpoint starts at Professional Plus.
- The free plan is 100 requests and non-commercial; the homepage text mentions 1,000 free monthly requests and subscriptions from $9.99, which the pricing page does not show.
- Each address checked counts as one API request; overage is listed as a per-request charge on the pricing page.
- Yearly billing is discounted by 10% to 15% depending on the plan.
Key features
Kickbox
- List verification
- Upload a list and Kickbox sorts each address by deliverability; the vendor says 100,000 addresses take about an hour.
- Verification API
- Checks addresses at sign-up in real time, with a sandbox mode for testing without spending credits and a free endpoint for spotting disposable domains.
- Threat Score
- Flags addresses linked to abuse, complaints or a poor sending reputation, for one extra credit only when a threat signal is found.
- Native integrations
- Verifies lists inside Mailchimp, Klaviyo, HubSpot, Braze, Iterable, SendGrid and others, with more through Zapier.
- Deliverability consulting
- Deliverability audits and consulting from Kickbox's own team are offered as a separate service beside verification.
mailboxlayer
- Syntax and typo check
- Validates format and returns a did-you-mean suggestion for common typos.
- Real-time SMTP check
- Pings the address's mail server and tests it for catch-all configuration; catch-all detection is not in the free plan.
- Free and disposable filters
- A daily-updated provider database flags addresses at free providers such as Gmail and at disposable ones such as Mailinator.
- Role detection
- Flags role addresses that map to a function instead of a person.
- Quality score
- Each response includes a numeric score for the address's quality and deliverability.
- Usage statistics
- Daily and monthly request counts, with notifications when a plan's allowance runs low.
Plans
Kickbox
Pay as you go$5
one-time for 500 verifications
Larger packs cost less per check: $10 for 1,000, $70 for 10,000, $500 for 100,000 and $2,999 for 1 million. Unknown results are refunded.
CustomCustom
Volume pricing for more than 1 million verifications, through sales.
mailboxlayer
Free$0
100 API requests, non-commercial use, no support, no catch-all detection.
Basic$14.99
per month for 5,000 requests, billed monthly
Commercial use, standard support and catch-all detection. Yearly billing is $161.99.
Professional Plus$74.99
per month for 50,000 requests, billed monthly
Adds a bulk endpoint that takes 25 emails at a time. Yearly billing is $787.99.
Enterprise Plus$249.99
per month for 250,000 requests, billed monthly
Bulk endpoint of 100 emails per call. Yearly billing is $2,549.99.
CustomCustom
Unlimited requests and dedicated support, quoted by the vendor.
Ways to pay less
Kickbox
- Nonprofit
15% off for nonprofits
Kickbox gives nonprofit organizations a 15% discount on verification.
mailboxlayer
- Annual discount
Save 10% to 15% with yearly billing
The pricing page shows yearly totals with discounts of 10% (Basic), 12.5% (Professional Plus) and 15% (Enterprise Plus).
Common questions
Which is cheaper, Kickbox or mailboxlayer?
As of Nov 12, 2026, Kickbox starts at $5 one-time for 500 verifications, and mailboxlayer starts at $14.99 per month for 5,000 requests.
Which has a free plan, Kickbox or mailboxlayer?
As of Nov 12, 2026, only mailboxlayer has a free plan. Kickbox does not, though it has a free trial.
More comparisons
How this page was made
- The verdict at the top follows a fixed rule. When both tools are in the same category and either is in our top three for it, the verdict follows that ranking: the higher-placed tool is our pick. The top three weigh who each tool suits as well as its grades, so a pick can go against the GPA. Otherwise the page does not pick one and says which grades higher: the higher GPA first; on a tie, the one with a free plan, then the one that starts cheaper in dollars a month, counted the same way for both; if they are still level, what the choice depends on.
- The grades are our own, from each tool’s review or report card. The GPA is their average.
- Prices, plans and platforms come from each tool’s listing. The table above says where each price was read and when.
- The differences and the answers to the questions are worked out from those listings.