Fonts - mailboxes

Good morning!

I'm trying to adjust the fonts used in various displays.    Mailboxes, for example.

I seem to have adjusted some fonts - smaller is my choice, given my screen resolution - but the mailbox display font is still very big.

How to change that?

Thanks

This in the Help guide under Fonts:

"...assigning specific font size for particular mailbox summary, use View/Text Size menu.

Hold down Shift key and click View/Text Size to assign new text size for all mailboxes (or currently open mailboxes only)."

I am looking for an adjustment to the actual message itself! So are so small it is unreadable.