isitdisposable vs Kickbox
Kickbox is a well-known email verification service offering syntax, MX, SMTP, and catch-all checks, plus a free disposable checker as a lead-in. Its product centers on deliverability and list hygiene.
| Dimension | Is It Disposable | Kickbox |
|---|---|---|
| Primary purpose | Real-time disposable and deliverability detection at signup | Bulk and real-time email verification (list cleaning) |
| Detection method | DNS-level (MX, A, AAAA). No SMTP mailbox probing, ever | Includes SMTP mailbox probing, catch-all, and spam-trap checks |
| Over-quota behavior | Fails open with a safe allow (HTTP 200), so your form never breaks | Per-credit or per-plan; behavior on exhaustion varies |
| Enforcement model | Per-account policy maps every signal to allow, warn, or block | Returns a status or score; enforcement is left to you |
| Signals returned | Disposable, deliverability, relay, public provider, role, typo, spam risk | Verification status, syntax, MX, catch-all, role, disposable |
| Integration | Drop-in JavaScript snippet, REST API, and a batch endpoint | REST API and bulk upload; some offer a free browser checker |
| Logging and privacy | Domain-only logging by default; stricter no-storage mode available | Varies by provider; review their data policy |
When Kickbox might be the better fit
If you need a deliverability-focused verification suite with a sending-reputation angle, Kickbox is a mature option.
Where signup protection differs
Whatever you pick, three things matter at the signup form specifically, and they are the three we put in writing:
Fails open, guaranteed
Over quota or during an outage you get a safe allow, clearly marked unchecked. A signup is never lost to a detection dependency.
Your policy, not a score
Every signal maps to allow, warn, or block in your own policy. We return the action; your form enforces it.
Domain-only logging
Request logs never store the part before the @. The opt-in no-storage mode keeps only the verdict and billing metadata.
Try the real engine for free
The demo runs the live detection engine - no account needed. Sign up for a 14-day full-access trial to see the full product, then stay on the Free plan or upgrade.
Comparison based on public information and our June 2026 research; competitor features and pricing change, so verify current details on their site. See other comparisons.