ZapBounce vs Mailfloss
Mailfloss solves a scheduling problem more than a verification one. It sits on your ESP and cleans continuously, so the list never rots between manual runs. That is a genuinely different product from an API you call, and the comparison is really about whether your problem is knowing or remembering.
| ZapBounce | Mailfloss | |
|---|---|---|
| Accuracy reporting | Coverage stated: the share of your list with a definite verdict | None published, and their FAQ explains why |
| 1,000 addresses | $5 | $8 prepaid |
| 10,000 addresses | $25 | $40 prepaid, or $29 a month on Lite |
| 100,000 addresses | $139 | $300 prepaid |
| Free tier | 100 a month, no card | 500 verifications a month, recurring, no subscription |
| Credit expiry | Never | Prepaid credits never expire |
| Billed for unknowns | No | Not stated |
Mailfloss figures read from their own pricing page in September 2026.
How Mailfloss prices it
Two models side by side. Prepaid credits run $8 for a thousand, $40 for ten thousand, $300 for a hundred thousand, and never expire. Subscriptions start at $29 a month for ten thousand credits and need a supported ESP connection to work at all, which makes the cheaper-looking option conditional on your stack.
Why teams pick ZapBounce over Mailfloss
What changes when your list runs through ZapBounce instead.
The short version
- Lower at every prepaid tier: $5 against $8 for 1,000, $25 against $40 for 10,000, and $139 against $300 for 100,000.
- No ESP required. Their subscription plans need a supported ESP integration; ZapBounce works from any CSV or API call, whatever platform you send from.
- Unknowns are never billed. Their pages do not state a policy either way.
- Typo suggestions without silent edits: the result flags the address and nothing in your list changes, so you apply any fix yourself.
- Every row carries the literal SMTP code the server returned, so any verdict can be audited line by line.
Moving off Mailfloss
The ESP requirement, as often as the price. Their subscription plans need a supported integration, so a team on an unsupported platform is pushed onto prepaid credits and loses the automation that was the reason to be there.
Unusual, because you are not replacing a verifier so much as removing an automation. Turn it off and list cleaning goes back to being something a person schedules. If nobody owns that task afterwards, the list decays quietly and the migration has cost you more than it saved.
The hard addresses, and how they come back
Questions people ask about Mailfloss
Is continuous cleaning better than a periodic bulk run?
For a list that grows daily, usually yes, because the decay never accumulates. For a list that receives one import a quarter, a bulk run at import time does the same work and costs less. Match the cadence to how your list actually changes.
Which is cheaper, their credits or their subscription?
Depends on whether your list changes. Ten thousand prepaid credits cost $40 once; the Lite plan is $29 a month for the same allowance, renewing. If you clean twice a year, prepaid wins easily. If the list moves daily, the subscription is buying the automation rather than the checks.
Does automatic typo correction ever get it wrong?
Any automated repair can. The confident cases are common domain misspellings, where the intended value is unambiguous. Ask them how the edge cases are handled before you let anything rewrite addresses in a live list.
Is ZapBounce cheaper than Mailfloss?
At 100,000 addresses we list $139 and they list $300 prepaid. Compare the per-address rate rather than the headline, and check what each side does with unknowns: ours are never billed.
Can I test both before deciding?
Yes, and you should. Run the same sample of a few thousand addresses through each and compare how many came back unresolved. That difference matters more than either accuracy claim.
Ask yourself whether your list rots because you do not know which addresses are dead, or because nobody runs the clean. Those are different products.
Run the same sample through us and Mailfloss
100 free checks a month, no card, and the unknowns come back labeled.