Change default "Image Sizes" Small, Medium, and Large in Mail

Hello,

I would like to change the Small, Medium, Large Image Sizes to my personal preference. Is this possible? If so, where might I find these settings, or how might I change it up?

Just to clarify, I am referring to the little drop down menu in Mail in the bottom right hand corner that appears after an image has been attached for the purpose of sending. See screenshot. I want to change those defaults.

Thank you 😀