RocketVerifier vs Mailfloss
The best Mailfloss alternative
Free unknowns, a verdict on every catch-all and automatic bounce refunds, for every workflow, not only list syncs.
100 free credits · No card required
Why teams switch from Mailfloss
- Unknown results are never charged, and every catch-all address gets a send_safe, send_with_caution or avoid verdict.
- Bounces on deliverable results are refunded automatically. Mailfloss's terms rule out any obligation to refund.
- A real-time API that typically answers in under 400ms, with RocketShield form protection on every plan.
- A hosted MCP server, RocketVerifier Connect OAuth and deliverability monitors are included.
Side by side
RocketVerifier vs Mailfloss
What you get for every credit, with Mailfloss's terms taken from its own published pages.
| Compare |  RocketVerifier | Mailfloss |
|---|---|---|
| Unknown results | Never charged, and duplicates in a list are free too | Billing of unknown results is not stated; a credit is one address verified. source |
| Bounce refunds | Automatic: every hard bounce on a deliverable result is refunded within 30 days when you connect SendGrid, Mailgun, Amazon SES or Postmark | No bounce guarantee; its terms say Mailfloss has no obligation to provide a refund or a credit. source |
| Catch-all addresses | Every one scored 0 to 100 with a send_safe, send_with_caution or avoid verdict, in the standard 1 credit | Catch-all handling is not described on its pricing, features or API pages. |
| Real-time speed | Typically under 400ms, or 1 to 3 seconds with a live SMTP check | No response time is published. |
| MCP server for AI agents | Hosted MCP server for Claude, ChatGPT, Cursor and any MCP client, plus a local npm package | No MCP server is listed on Mailfloss's site. |
| OAuth for third-party apps | RocketVerifier Connect: apps connect in one click and verify on the user's own credits | No OAuth app platform for third-party developers is published on Mailfloss's site. |
| Credit expiry | Pay-as-you-go credits never expire, and plan credits roll over | Prepaid credits do not expire; rollover of subscription verifications is not stated. source |
| Form protection | RocketShield, included on every plan | Instafloss, a JavaScript snippet for opt-in forms; plan inclusion is not stated. source |
| SPF, DKIM and DMARC | Free lookups plus deliverability monitors with alerts, included | No SPF, DKIM or DMARC tools are listed. |
Why RocketVerifier
The most accurate verifier, with everything included
99.5% accuracy, the fastest real-time API and the best verification infrastructure. No feature gating and no surprises on your invoice.
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Pay only for usable results
Unknown results and duplicate addresses are never charged. Connect your sending platform and every hard bounce on an address we marked deliverable is refunded automatically.
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A verdict on every catch-all
Accept-all addresses are scored 0 to 100 and get send_safe, send_with_caution or avoid, in the standard 1 credit.
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The fastest real-time API
Typically under 400ms, 1 to 3 seconds with a live SMTP check, and up to 100,000 emails per hour in bulk.
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Built for AI agents
A hosted MCP server for Claude, ChatGPT and Cursor, and RocketVerifier Connect OAuth for apps that verify on their users' credits.
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Credits never expire
Pay-as-you-go credits stay until you use them. Monthly and yearly plans roll unused credits over.
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Everything on every plan
RocketShield form protection, integrations, monitors, SDKs and the full API are included with every plan.
Migration
Switch in an afternoon
Move from Mailfloss without rebuilding your workflow. Verify a sample, see the difference, then switch over.
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Export from Mailfloss
Download your list from Mailfloss as a CSV. Any column layout works.
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Upload to RocketVerifier
Drop in a CSV, TSV, TXT or Excel file of up to 50 MB, map the email column and preview the result for free before you confirm.
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Download clean results
Get status, sub_status, score, provider and catch-all verdict for every address, ready to import anywhere.
Calling Mailfloss from your own code? Build against a free rv_test_ sandbox key, then swap in your live key. Using HubSpot, Mailchimp, Zapier or another tool? Connect it in a few clicks from the integrations page.
FAQ
RocketVerifier vs Mailfloss FAQ
Common questions from teams moving from Mailfloss to RocketVerifier.
Why choose RocketVerifier over Mailfloss?
RocketVerifier never charges for unknowns, scores every catch-all with a send verdict, refunds bounces on deliverable results automatically and covers every workflow: bulk lists, a real-time API under 400ms, form protection, integrations and AI agents.
Mailfloss facts are taken from Mailfloss's own published pages, checked November 1, 2026. Sources: mailfloss.com/pricing, mailfloss.com/features.
Switch from Mailfloss today
Verify a sample of your list and see the difference. Unknowns are free, bounces are refunded and credits never expire.
100 free credits · No card required · Credits never expire