CRM Database Cleanup & Validation

I have an exported client list that I need ready for a smooth import into our CRM. Right now the file is riddled with incorrect data—particularly within the email addresses, account name and names columns—and I keep bumping into duplicates and stray characters that the system refuses to accept... (Budget: $30 - $250 USD, Jobs: CRM, Data Analysis, Data Cleansing, Data Extraction, Data Management, Data Mining, Data Processing, Excel, LinkedIn Profile, MySQL)