If your source data is in Excel and has duplicates, run Power Query to remove those duplicates before running a Word mail merge.

Microsoft Excel is perhaps the most powerful spreadsheet application you can buy. But it also has some simple functions, like finding duplicates in data.

How to remove duplicates in Excel for a single column When you have duplicate data that you want to remove from a single column in your dataset, start by clicking into the column you want to dedupe.

If sync software or some other anomaly has peppered Outlook with duplicate entries, use this fast, free utility to get rid of them.

This option only appears if Excel detects data adjacent to the selected column. Uncheck all columns except the one containing the consolidated data and click "OK" to remove duplicates.

How to Merge and Remove Duplicate Contacts on your Mac As with any computer procedure that involves deleting data, make sure you have a backup of your system before following these steps.