A retail company's database of record resides at a third party company that also keeps track of purchase history. Their database only updates once a day where new records can be created and merged. The database uses the unique identified "Customer ID". The company wants to send real-time Welcome emails to newly registered website users who provide their email address in exchange for getting 10% off their first order, and ensure this send is connected to "Customer ID" in the database. What three key issues should be addressed? (Choose three.)