Set default zoom level on mail preview pane

Is there a way to do so? I have googled it, but couldn't find anything
I know you can press command +, but it's a hassle to do it for every email, any suggestions are appreciated

 

Thanks for all the reply, and I have tried that before. But for the most part, it seems that this only work for the name field and the subject field but doesn't work for the content of the emails. My guess it's because the emails are not plain text, but HTML formatted? So I'm hoping to set the zoom level, say to 150%, so the content will also be zoomed

 

Any more suggestions other than adjusting the font size? Thanks