@colegota Thank you for the tip. "Send Reduced" open source application. available via F-Droid, can be used to reduce size of attached images on the fly.
Even if you attach an image to your draft message, you can select "Get Reduced Photo" from a list of sources. As I did in this post.
As I see, the "Send Reduced" application is not that simple, including its settings. So maybe there is no real point to implement the same feature inside AndStatus?!
@escobrice https://loadaverage.org/attachment/3029567