Checking mailboxes directly from your own n8n or VPS server gets its IP blocked by Spamhaus. NoBounce runs syntax, MX, disposable, catch-all, and mailbox verification from clean infrastructure and answers inside your workflow.
When a mail server blocks probing, NoBounce returns unknown or catch_all — never a false valid.
Drop our official n8n-nodes-nobounce node or HTTP Request step into your enrichment flow to verify leads inline.
Distinguishes confirmed mailboxes (valid), non-existent users (invalid), catch-all domains (catch_all), and blocked servers (unknown).
Automatically rejects 150+ throwaway inbox providers (Mailinator, Guerrilla, YOPmail) and suggests fixes for domain typos.
GET /api/validate?email=prathap@nobounceapi.com&smtp_check=true
valid, invalid, catch_all, or unknown (never returns valid if the mail server could not be verified).
{
"email": "prathap@nobounceapi.com",
"status": "valid", // "valid", "catch_all", "unknown", "invalid", or "valid_domain"
"sub_status": "mailbox_exists", // "mailbox_exists", "mailbox_not_found", "catch_all_domain", "disposable_email", "typo_detected", "mailbox_unverified"
"is_valid": true,
"is_catch_all": false,
"is_disposable": false,
"is_role_based": false,
"free_email": false,
"mx_found": true,
"smtp_check": true,
"smtp_status": "valid_mailbox",
"verification_time_ms": 68,
"did_you_mean": null
}