Email Verification Services: Tools like NeverBounce and ZeroBounce can verify and clean your email list. CRM Systems: Customer Relationship Management (CRM) systems like Salesforce and HubSpot can help manage and update your data. Analytics Tools: Tools like Google Analytics can provide insights into user behavior, helping you identify inactive subscribers. Email Marketing Platforms: Platforms like Mailchimp and Constant Contact often offer built-in data cleaning features.