If you know you'll be using Excel or Outlook as the source of your data, see: If you don't yet have a data source, you can even type it up in Word, as part of the mail merge process.įor details about data sources, see Data sources you can use for a mail merge. Excel spreadsheets and Outlook contact lists are the most common data sources, but any database that you can connect to Word will work. Your first step in setting up a mail merge is to pick the source of data you'll use for the personalized information.