Kickbox is an email verification platform built for developers and data-driven marketing teams. Its standout feature is the Sendex score — a proprietary deliverability rating that goes beyond binary valid/invalid to predict how likely an email is to be delivered and engaged with. Kickbox is trusted by over 100,000 businesses and known for its clean API and transparent pricing.
Product Overview
Kickbox verifies email addresses individually or in bulk, returning a rich set of results: verification result, Sendex score, disposable detection, role-based address flagging, and free email provider detection. Teams can use the REST API to verify emails at the point of capture in any application. The platform also offers inbox placement testing and deliverability consulting for teams serious about email performance.
Key Features
- Sendex Score: Proprietary 0–1 deliverability score that predicts inbox placement quality beyond a binary pass/fail.
- Single & Bulk Verification: Verify one address via API or upload lists of any size via the dashboard with fast turnaround.
- Disposable & Role-Based Detection: Automatically flags temporary email addresses and role accounts (info@, admin@) that lower engagement.
- REST API: Clean, well-documented API with client libraries for Node.js, Python, Ruby, PHP, and more.
- Inbox Placement Testing: Test how your emails land across 40+ inbox providers before sending to your list.
Best For
Development teams building email capture workflows, and marketing teams that want a nuanced quality score rather than a simple valid/invalid result.
Pricing
Pay-as-you-go: $5 per 500 verifications up to $1,500 per 500,000. Volume discounts available. Free 100 verifications on sign-up.
Key Integrations
Zapier, Mailchimp, HubSpot, Segment, REST API (any platform)
Pros
- Sendex score is a unique differentiator
- Developer-friendly API with good documentation
- Transparent pay-as-you-go pricing
- Inbox placement testing included
Cons
- No native sync with email platforms (unlike NeverBounce Sync)
- Smaller ecosystem of direct integrations
- Deliverability consulting is an add-on cost
