Thank you (!)

I would take an estimated size funtion very eagerly (!)

Right, in a perfect world there would be a function on the optimization area where you could choose the final file size
yourself and not deal with the different variables and try to get them to fit your need.

Success (!) With 72 dpi, 72 dpi and low quality I could get the largest file of 147 M to 2.09 M, I guess there is no way of knowing what the final size (if you are attempting to go to the range of 2.0 - 2.5 M) will be other than trying out different options (?)

Okey, I´ll try to learn that feature...

What is the easiest way to reduce the file size dramatically from exhibition sized posters to email attachment range (?)

Okey, thanks for your answer...

The program seems to be capable of converting single pages from multipage .pdf to image files (eg .png) easily and quickly so that resulting files contain one page, also complete multipage .pdf files can be converted to a multipage .doc in an instant, but to complete that procedure for a single page...