Large Contact Database Cleanup, Deduplication & Email Validation

I have an Excel file with roughly 20,000 contact records that must be immaculate before it reaches our CRM. The task goes well beyond a basic trim-and-sort: • Detect and merge true duplicates, repair any corrupted fields, and remove bad or placeholder data... (Budget: $250 - $750 USD, Jobs: CRM, Data Analysis, Data Cleansing, Data Integration, Data Management, Data Processing, Email Handling, Excel, Linkedin, Web API)