Mail merging is simple on Mac, but many people face issues. The most common problem the users have faced is that the Mail merge not working on Mac due to using the Mac version, Mac 16.39, for Mail merging in Word. Go to Finder, then Applications, and then 'Find Word Application' to get back to the previous version of Word for Mac, which is 16.38. Give 'Word' a new name that will be easy to remember. Download and install the earlier Word version for Mac, version 16.38. Follow all of the instructions for installing the previous version. And the problem was solved by installing a newer version.