Niklas,
What you want to do is possible, but more complex if you want to generate csv files and then have NPrinting just take care of delivery. I would consider the solution below a workaround and there are a few assumptions:
1) Each CSV file is already filtered in the appropriate way for a specific client
2) Each CSV file is saved to a different directory or is named in a different way from every other csv file
3) The CSV files are always saved to the same location and always have the same name each time they are built
If all of the above conditions are true, then you could build a Report Task for each client and simply attach that client's csv file to the email for their Task. The hard part is that if there are say 500 clients, then you'd have to manually build 500 Report Tasks and you would have to maintain these Tasks (adding a new client = adding a new Task...)
With my original solution, maintenance can be easily automated assuming you have a way of associating the Client with their email address and the field name(s) and value(s) on which you want to filter for that specific client.
Best
Aran
