FazeVerify is a contact-data verification service for teams that want to protect email deliverability and maintain reliable mailing lists. It checks addresses through a six-step process, including syntax and domain checks, mail-server lookup, and an SMTP conversation with the receiving server. The service asks whether a mailbox exists, then disconnects without sending a message. Each address receives a verdict—deliverable, risky, invalid, or unknown—along with the reason behind it. FazeVerify also identifies spam traps and disposable addresses, helping businesses distinguish reputation risks from ordinary invalid addresses.

Teams can verify lists in bulk or check addresses as they are added through an API, webhooks, and signup forms. FazeVerify connects with services and data sources including Mailchimp, HubSpot, Brevo, Klaviyo, Airtable, Google Sheets, Shopify, and databases. Verdicts can be written back to supported sources, and scheduled re-verification helps account for list decay. Unknown results are requeued and not billed. The service offers a free start and paid plans for ongoing verification, with configurable data retention and purging options.