Well, since this is 10 years old I will post a more updated solution… As you might already know IBM Notes natively supports printing a very limited set of basic labels specifically supporting mail merge data in the Contacts (Personal Address Book). You must download the tool below to support mail merging to the latest labels including barcoding. i.e. USPS Intelligent Mail barcoding (IMb). It supports Notes (Standard) and Notes (Basic) running on Windows with Word 2016/2013/2011/2008/2007/2003 installed.
Print Merge Reporter for IBM Notes - Mail merge, printing and reporting tool
• Mail merge Excel, contacts, barcodes and Notes app data to email or printer using Notes, iNotes, web
• Generate charts and reports to Word, Excel, and PDF format using Notes, web
• Export Notes app and Contacts data to Excel