ok, ok_for_all, valid - the server is saying that it’s ready to receive a letter to this address and no tricks are detected.

unknown - this often happens if the destination mail server is too slow or temporarily unavailable. In some cases, retrying your request after about 5-15 minutes will return a valid or invalid response.

Invalid - the server is saying that delivery will be failed

Syntax error - syntax error in email address.

email_disabled - email account is suspended/disabled/limited and can't receive emails.

not_validated - it means that this email was not yet verified in LeadRocks. You should initiate this process again. you can read more about the verification process here: https://help.leadrocks.io/en/articles/6280893-email-list-verification-how-it-works