In the Mail Merge Helper dialog box, click Get Data and select Use Address Book . The Use Address Book dialog box appears with the available address books listed under Choose Address Book . Select the Address Book you want to use as your data source. Word may prompt you to confirm the data source if Confirm Conversions is selected as an option. If you use an address book from Exchange, Word prompts you to log on to the Exchange services.
Word displays a message to set up the main document.
Click Set Up Main Document . In the Mail Merge Helper, under 1. Main document , click Setup . Word displays the Label Options dialog box. If you are using a custom label, click Details and enter the size of the label.