> When you open
> 
> <https://impulse.news-mailer.com/u/archive/8yfFA1RRSM>
> bdQR7YfftNbQ
> 
> an make a right-click on any picture in it like
> 
> <https://images.maileon-static.com/c/zal814kuI_dHJO3D>
> R6z99A
> <https://images.maileon-static.com/c/AWn6DIky2iOupCfT>
> d27jvA
> etc.
> 
> these are the files that are not saved.
> 

Sorry, but I cannot reproduce this. All the images in my case are stored in
the domain: <https://impulse.news-mailer.com>
such as:
<https://impulse.news-mailer.com/u/archive/8yfFA1RRSMbdQR7YfftNbQ>
<http://impulse.news-mailer.com/c/DwtvHjtHhbmjLvqCNTtuEg>

Based on this, I think, the webpages are generated dynamically. And I'm out of
idea.