Mailsurity vs Kickbox
Kickbox is a well-established, full-stack email verification platform built around syntax checks, MX lookup, a well-known open-source disposable-domain list, and mailbox-level SMTP-ping checks (pinging the receiving mail server to confirm an exact address is real, not just well-formed), all bundled into one deliverability tool. Mailsurity does one thing: catch disposable, temporary, and fake signups, including the brand-new domains a syntax-and-list checker hasn't seen yet. If you're looking specifically at a Kickbox alternative for that one job, that's the comparison below.
Quick verdict
Choose Kickbox for full-stack email verification
You need full list hygiene before a marketing send (syntax validation, MX checks, and mailbox-level verification to cut bounce rates), with disposable detection as one part of that pipeline.
Choose Mailsurity for disposable email detection
You specifically need to stop disposable/burner signups in real time, at the signup form rather than a batch-cleaned list, and want brand-new throwaway domains caught before a static list catches up.
Pricing
Kickbox charges per verification, pay-as-you-go. Mailsurity is a monthly credit subscription with a free tier to start. Figures below are Mailsurity's live current prices, not estimates.
Kickbox
Not verified; see kickbox.com for current free-tier terms
~$0.008 / verification, $10 / 1,000 credits†
Mailsurity
500 free credits, 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.
† Kickbox publishes two pay-as-you-go figures: ~$0.008 per verification, and $10 per 1,000 credits. Taken literally those don't match (0.008 × 1,000 = $8, not $10, a $2 / 25% gap we can't attribute to a specific cause, e.g. a minimum-purchase increment, without confirming it on kickbox.com). We use the $10-per-1,000 figure as the comparison row above since it's the number directly comparable to Mailsurity's own cost-per-1,000 metric; confirm both figures on kickbox.com before comparing at your specific volume.
Prices shown are Mailsurity's current live plans (see /pricing for the full breakdown, including annual billing); Mailsurity pricing verified July 2026. Kickbox figures are verified as of July 2026 too; confirm current rates on kickbox.com before making a purchasing decision, as vendor pricing can change.
Feature comparison
Primary focus
Kickbox: Full-stack email verification (syntax, MX, mailbox ping, deliverability)
Mailsurity: Disposable / temporary / burner email detection, specifically
Disposable-domain method
Kickbox: Curated disposable-domain lookup (Kickbox maintains a well-known open-source list)
Mailsurity: 5 checks in order: your team's own allow/deny rules, a curated known-good list, a 220k+ domain disposable list, a saved verdict from a past check, then live analysis (with AI for unclear, brand-new domains)
Brand-new throwaway domains
Kickbox: Caught once added to the list
Mailsurity: MX-cluster reputation (tracking which mail servers throwaway-email providers tend to reuse) + AI gray-zone fallback (an AI check for domains the heuristics can't confidently call either way) can flag a domain before any static list has it
Mailbox-exists / SMTP ping checks
Kickbox: Yes — mailbox-level SMTP verification (pinging the receiving mail server to confirm an exact address exists, not just its domain) is part of full-stack email verification
Mailsurity: No, Mailsurity does not verify mailbox existence, only disposable/legit classification
Bulk CSV list cleaning
Kickbox: Yes — bulk list verification and its real-time API are the two products Kickbox highlights on its own site
Mailsurity: Yes, enriched CSV back with classification, confidence, and source per row
Typical latency
Kickbox: Not published
Mailsurity: <100ms p99 on the real-time API
Free tier
Kickbox: Not verified; see kickbox.com for current free-tier terms
Mailsurity: 500 free credits, no card required
The entire Mailsurity integration is one authenticated POST with plain fetch. No client library required.
curl -X POST https://www.mailsurity.com/api/check-email \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"email": "user@mailinator.com"}'Example response:
{
"email": "user@mailinator.com",
"isDisposable": true,
"classification": "disposable",
"confidence": 0.94,
"reason": "high-entropy local part; MX cluster flagged disposable",
"source": "heuristic"
}Full request/response schema, error codes, and code samples in eight languages: see the API reference.
Why list-based disposable email detection misses new domains
Kickbox's disposable lookup draws on a well-known, actively maintained open-source domain list, a solid foundation that many other tools (including parts of Mailsurity's own list) also draw from. The gap with any static list is timing: a brand-new throwaway domain has to be discovered and added before it can be blocked.
Mailsurity layers MX-cluster reputation and an AI fallback for gray-zone domains (ones the heuristics can't confidently call either way) on top of its own list, so a domain can get caught on its first request, before it's ever been added to any list, Kickbox's or Mailsurity's own. See the full 5-layer detection cascade for how each layer works.
220k+ tracked domains
Sourced from public disposable-domain feeds and live throwaway-provider scraping, kept current as new ones appear.
99.4% accuracy
Measured on disposable/temporary email classification, the one thing Mailsurity is built to do.
FAQ
Is Mailsurity a good Kickbox alternative?
It depends on what you need Kickbox for. If you need full email-list hygiene, syntax checks, MX lookup, and mailbox-level SMTP verification, Kickbox and other full-stack verifiers cover that and Mailsurity doesn't try to replace them. If what you actually want is a focused Kickbox alternative for disposable/temporary/burner email detection specifically, including brand-new throwaway domains a static list hasn't caught yet, that's the one job Mailsurity is built around, with a 500-credit free tier to try it first.
Is Mailsurity cheaper than Kickbox?
It depends on volume. Kickbox charges a flat ~$0.008 per verification ($10 per 1,000 credits) no matter how much you use. Mailsurity is a monthly credit subscription with a 500-credit free tier and no card required to start; see the live plan pricing above to compare at your own volume.
Does Mailsurity verify mailboxes the way Kickbox does?
No, and we don't pretend to. Kickbox's mailbox/SMTP-ping checks are part of its broader deliverability product. Mailsurity only classifies whether a domain is disposable, temporary, or legitimate. If you need mailbox-level verification, Kickbox (or a similar full-stack verifier) covers that; Mailsurity is built for the disposable-detection layer specifically.
Can I use Mailsurity and Kickbox together?
Yes. Some teams run Mailsurity at signup time for real-time disposable detection, including brand-new domains a static list hasn't seen yet, and use Kickbox separately for periodic list hygiene or mailbox verification. The two aren't mutually exclusive.
Will Kickbox's open-source disposable list catch the same domains Mailsurity does?
For domains already on that list, yes: Mailsurity's own list draws on the same kind of public feeds as one layer of its cascade. The difference shows up on domains no public list has yet. Mailsurity's MX-cluster reputation and AI gray-zone fallback (its check for domains the heuristics can't confidently call either way) can flag those on the first request, where a static list has to wait until someone adds the domain.
See how many disposable signups are slipping through right now
Paste your signup list into the free audit: no signup required, and the part before the @ never leaves your browser. Or start with 500 free API credits, no card required.