AtData is a technology-driven provider of email address solutions for first-party data, offering services like email validation, data enrichment, identity matching, and fraud protection. AtData is an email-data/marketing intelligence provider. The only thing the provided page indicates is a "Privacy Web Form" for submitting privacy requests; no details on identity verification, response time, or scope were included, so start at AtData's privacy page and look for that form. Because AtData continually ingests email and marketing data from partners, it's worth re-checking your suppression status roughly annually.