expression.SetAllIncludedFlags(Included)
expression Required. An expression that returns a MailMergeDataSource object.
Included Required Boolean. True to include all data source records in a mail merge. False to exclude all data source records from a mail merge.
Remarks
You can set individual records in a data source to be included in or excluded from a mail merge using the Included property.
Example
This example marks all records in the data source as containing an invalid address field, sets a comment as to why it is invalid, and excludes all records from the mail merge.
Sub FlagAllRecords()
With ActiveDocument.MailMerge.DataSource
.SetAllErrorFlags Invalid:=True, InvalidComment:= _
"All records in the data source have only 5-" _
& "digit zip codes. Need 5+4 digit zip codes."
.SetAllIncludedFlags Included:=False
End With
End Sub