Mail Merge, WordprocessingML, and Hosting Applications
The two key parts of the mail merge process are:
Connecting to an external data source
Populating mail merge fields with external data
It is important to note that aspects of the mail merge process outside of connecting to an external data source and populating mail merge fields with external data, are at the discretion of the hosting application.
As an additional example, WordprocessingML provides an element to be used as a flag by hosting applications to specify action to be taken on the merged documents that are generated by a mail merge. In other words, performing actions such as:
creating a new document for each merged document
generating and sending emails containing merged document
printing merged documents
may be specified through WordprocessingML, but what if any specific action is taken on merged documents is determined by the application.