I have exported customer data from two separate files in our accounting system to Excel. The "masterfile" worksheet contains the customer number, company name, address, city, state, zip information. The "contact" worksheet contains the customer number, contact name, phone, email. The one common field in both worksheets is the customer number. There is only one record per customer in the masterfile worksheet. But there can be many records per customer in the contact worksheet. I would like to be able to do an email blast using the data in the contact worksheet, but also include the company name which is located in the masterfile worksheet. How can I link on the customer number so that I can steal information from the masterfile worksheet when I am using the contact worksheet as the data source for my mailing?