valid
: The recipient’s mail server has confirmed that the email address is valid and safe to send to.invalid
: The email address is either incorrect or does not exist, meaning it cannot receive mail.risky
: This email address may have quality issues, potentially leading to bounces or low engagement. Risky categories include Accept All, Disposable, and Role-based addresses.unknown
: Proofy did not receive a response from the recipient’s server, possibly due to slowness or temporary unavailability. You may retry after 5 minutes. No credits will be charged for unknown results.