Email Blacklist Check That Screens Any Address in Seconds.

Yes. You can run 4 checks per day from this page without an account. No card, no signup, and each check runs the full blocklist and reputation scan, not a stripped-down teaser that nags you to upgrade before showing the verdict.

Create a free account and you get 1,000 checks on the spot, or 2,500 if your signup email is a work address. After that, credits are pay-as-you-go and never expire on any paid plan, with volume pricing shown for your region.

Nine checks run in parallel every time you run an email blacklist lookup, scoring both the address and the domain behind it: syntax and 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, an AI-confidence pass on catch-all addresses, domain age and reputation scoring, and blocklist (DNSBL) and sender-reputation signals.

The verdict folds blocklist signals and sender-reputation risk into one score, so a flagged domain reads as risky before you ever hit send. Median latency sits around 380 ms per address, so the full battery feels instant. If you just need to check one email address at a time, the checker runs the very same engine.

A domain or sending IP lands on a blacklist (a blocklist or DNSBL) when it trips a spam filter’s thresholds: high bounce rates, spam-trap hits, sudden volume spikes, or recipients marking your mail as junk. Spam traps are the sneakiest of those. They are addresses that exist purely to catch senders with bad hygiene, often recycled from long-dead mailboxes, so they never opt in and never bounce. Once listed, a large share of your sends quietly route to the spam folder or get rejected outright.

The single biggest controllable cause is sending to bad addresses. Run an email bounce check on the list before each campaign and you starve the bounce-and-complaint loop that gets domains blacklisted in the first place. A free email validator pass on inbound signups closes the other door.

Yes. The free tier gives you 1,000 checks (2,500 if you sign up with a work email), so this doubles as a bulk blacklist email check for most small lists outright. Each row comes back with the same blocklist and reputation verdict the single check returns, plus the per-check breakdown in the export.

For larger lists, our paid credit packs are pay-as-you-go and never expire, with pricing localized to your region on the pricing page. CSV upload, API access, and bulk parallel processing are included from the free tier up.

No. Every blacklist lookup is processed in memory and discarded the moment the verdict renders. We never log the address, never retain the result, and never sell anything. Checking whether a domain is blacklisted should not itself create a paper trail.

That matters more here than on a plain validity check, because people often screen their own company domain or a prospect list they are not ready to share. We’re SOC 2 Type II compliant, and the privacy policy spells out exactly what we touch and what we don’t.

Fix the root cause first, then request delisting. Most blocklists run a removal form on their site; the major DNSBLs delist automatically once the abusive pattern stops and your metrics settle, typically within a few days to a few weeks depending on the list and how bad the offense was. Submitting a removal while you’re still sending to dead addresses just gets you relisted, and repeat listings take progressively longer to clear.

So the durable fix is hygiene: scrub every list with an email verifier before you send, warm new domains slowly, and keep bounce and complaint rates low. After the delisting clears, watch the domain with the domain spam checker so a relisting never catches you mid-campaign.

They answer two halves of the same question. An email verifier tells you whether an address is real and reachable; an email blacklist check tells you whether sending to it (or from the same domain) carries blocklist and reputation risk. An address can pass one and fail the other: perfectly deliverable but parked on a flagged domain, or squeaky clean on reputation yet pointing at a dead mailbox. Verifox runs the identical nine-check engine for both and returns one verdict.

If you prefer the validation phrasing, the free email validator is the same tool under a different name. All three share the same accuracy, the same verification engine, and the same free tier.

A small handful carry most of the weight. Spamhaus (SBL, XBL, and the domain-level DBL) is consulted by the majority of mail servers worldwide; SpamCop and Barracuda matter for corporate gateways. A listing on a tiny hobby DNSBL that no provider queries is mostly noise, so don’t panic over every red row in a 100-list scan.

The bigger shift: Gmail and Microsoft now lean on their own internal reputation systems more than public blocklists, which is why Verifox folds DNSBL hits together with domain reputation signals into one verdict instead of handing you a raw list of acronyms.

Yes. The REST API reference documents the inbound and outbound shapes for every endpoint, so you can drop real-time blacklist and reputation scoring into signup forms, CRMs, or any tool that speaks REST. Screening at signup is the highest-value spot: rejecting a flagged or disposable address there costs milliseconds, while letting it into your sending list costs reputation later. HubSpot, Salesforce, Zapier, Klaviyo, Mailchimp, and Brevo all connect out of the box.

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

Weekly if you send regularly, and immediately after any deliverability symptom: open rates falling off a cliff, a spike in bounces, or replies saying your mail landed in spam. Blacklist listings often happen days before you notice the damage, so a standing weekly check is the cheapest early-warning system you can run.

Pair it with a periodic email health check on the addresses you send to, and an email deliverability test before any large campaign. Teams on the API simply schedule the lookup as a cron job and alert on any verdict change.