Hi ! I am a designer of a big company. We actually use Sketch to design our newsletters and i would like to propose to my team to switch for Adobe XD but it will be more easily if you have a plug-in for dartagnan. Dartagnan is a software we can upload our pictures and make our newsletter easily. But if we could import our design from Adobe XD, for sure we will switch for your software !
You can see what i mean with this exemple oof Letter : https://letter.so/xd/