Mail Fonts to small must like (O)

After the new update my receiving mail font when down almost to (o), I can able to read all about it. I try to locate where I can set and change the size but I wasn’t able to do the change. If anyone knows about it please, can let me know and help me.
Thank you

Right click in the body of a received email and then choose “Zoom”, then Increase or Decrease the font.
Alternatively, if you are in a Windows environment, you can click (and hold) CTRL+ or CTRL-.

A little confusing… it appears that prior to the update the incoming email body was the right size… is the font size shown in screenshot below the correct font?