You can personalize emails by using merge fields. Merge fields let you take customer information you already have in your QuickBooks company file and use it to make your customer feel as if you are talking directly to him. For instance, when you see Dear {First_Name|Valued Customer}, the first name of your customer will be inserted, providing you have a value for that field in your QuickBooks company file. If you don’t have a value, the Valued Customer phrase will be the default. These merge fields are inserted for you in your introduction, but you can further personalize your emails by inserting your own merge fields in the Subject line.
A sample of a good Subject line is: "Special thank you for {First_Name|Valued Customer} in time for the holidays!"