The Email Health Checker That Tells You If It's Safe to Send To.

An email health check answers one question: is this address safe to send to? It runs an address through syntax, DNS, SMTP, and risk checks, then returns a verdict on whether sending will land in the inbox, bounce, or hit a spam trap and drag down your sender reputation.

Verifox runs the same nine-check engine our paid Email Verification API uses, so the email deliverability check you get here is the same one teams pay for at scale. If you prefer the plain verify phrasing, the free email checker is the same tool under a different name.

It is, with no expiry trick. The checker above gives you 4 health checks a day without an account. When you hit that cap you can wait for the daily reset, or sign up free and claim 1,000 credits on the spot, 2,500 if you register with a work address. No card at either step.

Past the free credits, packs are pay-as-you-go and never expire. Pricing is localized to your region, which is why we never quote a flat figure here.

All nine checks from our verification engine fire in parallel on every address:

• Syntax + format validation (RFC 5321 / 5322)
• Domain existence and MX record presence
• SMTP handshake and mailbox-exists ping
• Disposable-domain match
• Role-address detection
• Catch-all domain detection
• AI-confidence scoring on catch-all addresses
• Domain age
• Email authentication (SPF, DKIM, DMARC)

The combined verdict scores 99.99 % accurate on our 1,000-address benchmark, and the catch-all resolution covers the spot where 20 to 40 % of B2B lists quietly rot. The free email validator runs this same pipeline under the validate phrasing.

Every hard bounce and spam-trap hit chips away at your sender reputation, and once it drops, even your healthy mail starts landing in spam. Mailbox providers watch your bounce rate closely; keeping it under 2 % is the practical line between the inbox and the junk folder.

A health check works on the address; pair it with our email deliverability tester to score your sending side, and the email bounce checker to flag the addresses already costing you. Together they keep a healthy email list earning inbox placement.

Risky means the domain accepted our SMTP handshake but would not confirm the specific mailbox, almost always a catch-all domain. The address might be live, might be a black hole. Our AI-confidence pass scores each one, so you get a probability instead of a shrug.

The practical rule: send to high-confidence risky addresses when the contact is valuable, hold the low-confidence ones back. Since 20 to 40 % of B2B lists sit at catch-all domains, blanket-deleting every risky address throws away real pipeline.

Before every major send, and quarterly at minimum. Addresses decay fast: people change jobs, mailboxes get retired, domains lapse. A list that was clean in January can be a bounce hazard by June.

The free signup tier (1,000 credits, or 2,500 with a work email) covers a full hygiene pass on most small lists, and bulk runs at roughly 10,000 emails per minute on the standard tier. If you would rather not remember a schedule, deliverability monitoring watches your sending health between passes.

Three main routes: recycled traps (providers retire a dead mailbox, then quietly reopen it to catch senders who never clean their lists), purchased or scraped lists that are seeded with pristine traps, and typo domains harvested from sloppy signup forms.

One trap hit can put your domain on a blocklist, so run an email blacklist check if your open rates suddenly crater, and check your email for spam triggers before the next campaign. At the source, our FoxGuard form widget blocks bad addresses before they ever reach the list.

Never. An address exists in our memory for the few hundred milliseconds the health check takes, then it is gone. No logs, no retention, no resale, and nothing for a breach to leak.

That posture is audited: SOC 2 Type II, with the Trust Center report available on request. The privacy policy spells out exactly what we touch during a check and what we refuse to keep.

In practice, nothing. An email health check, an email deliverability check, and email verification all do the same job: confirm an address is real, reachable, and safe to send to. Verifox runs the identical nine-check engine for every one of them. “Health” just frames the verdict around the outcome you care about, inbox placement, rather than a bare valid or invalid.

If you prefer the single-address, paste-and-go phrasing, the free email checker is the same tool, and the free email validator covers the validate-an-address phrasing. All three share the same accuracy, the same verification engine, and the same free tier.

Yes. The REST API reference documents the inbound and outbound shapes for every endpoint, so you can drop a real-time email health check into signup forms, CRMs, or any tool that speaks REST. HubSpot, Salesforce, Zapier, Klaviyo, Mailchimp, and Brevo all connect out of the box. Median latency is around 380 ms per address, sub-50 ms cached, with a 99.9 % uptime SLA on Starter and 99.99 % on annual Volume contracts (live status at status.verifox.ai).

Verifox also ships native MCP server support so AI agents (Claude, Cursor, custom LLM apps) can check address health without glue code. Drop the MCP URL into your agent config and the tools are wired.