## ExecuteWithRegions(*[IMailMergeDataSource](../../imailmergedatasource/)*) {#executewithregions} Performs a mail merge from a custom data source with mail merge regions. ```csharp public void Exe......Add(new Employee("Jane Doe", "Management")); EmployeeList employeesSeattleBran...Employee("John Cardholder", "Management")); employeesSeattleBran...