A verified lead is a lead whose contact email has been confirmed deliverable by a live check at the time you intend to use it: syntax, domain and mail server exist, the mailbox accepts the address, and the domain is not a catch-all. It differs from a lead that carries a data vendor's "verified" badge, which records when the vendor last looked. On non-freemail lists in 2026, 32.6% of addresses verified as confirmed valid, 14.5% were invalid and 27% could not be confirmed either way.
Verification returns one of a few states per address: valid, invalid, catch-all, unknown, and sometimes risky or role. A lead is verified only in the first state. The check is point-in-time; a result older than 90 days should be refreshed, since B2B addresses decay at the rate measured in BounceZero's decay study (only 19.2% of addresses still valid 90 days after a check).
The states matter for routing. Valid goes to cold sequences from the primary domain; catch-all and unknown to warm, low-volume or other channels; invalid is held or deleted. Email list verification explains what each result means and how a bulk job runs.
A sales team imports 4,000 leads from three sources and verifies them: 2,750 valid, 90 catch-all, 640 unknown, 520 invalid. The 2,750 are the verified leads. The team's dashboard now reports 2,750 reachable leads rather than 4,000 rows, and the forecast built on that number holds.
Verify a list or a single address. 100 free checks a month, unknowns refunded.
Verify Leads - FreeAyoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.