Wrong Picture Size all over MacOS Ventura

Hi, my Problem: I want to use a picture with 150px x 200px for my signature in Mail.

I safe the picture in photoshop in the right dimensions, but the picture is displayed much bigger, in preview and in mail. I goggled around and it seems this problem ist at least a decade old.

There is a workaround for displaying the picture in the right side in preview, you have to ad @2x before the extension, but how st... is that?

It is not possible to use the picture in the mail signature, because it is to big an you see the pixels.

Is there a fix for that?