Mamat,
What you will want to do there is go to the Page Ribbon and choose "Margins > Define" and turn off the "Print On One Page" option. That way you can see page margin lines on the work area. Once that is done, go back to the Page Ribbon and click the "Work Area" option and define the work area in pages across and down. You can then add and position the newsletter documents to each page on the work area. See if that helps.
Once you have that multi-page work area, the PDF filter will recognize that configuration and give you a multi-page PDF file.
Regards,
SmartDraw Support