Automatically download image in email from a specific sender

Hi,

I would like to set a rule that would automatically download image for a specific sender used for internal Newsletter.

I don't want to do it user per user (or computer per computer), I would like to find a way to do it at organization level.

Exchange Online : seems no option there

Add the entry to Outlook "Safe Senders List" through a GPO : the issue is that it would replace user Safe Senders List. So not an option too...

Anyone has an idea ?

Thomas