How do I change font size of my emails. Font size too small

-open mail/preferences/fonts and colors

-this gives you the options for all the fonts in different parts of the mail app, you can change the list view, composed messages, etc from here

Several days ago, we loaded Maverick. I have been in mail/preferences/fonts and colors, and my font size will not change either. I even tried switching to a different font (Arial) and changing to 24--nothing happened--36--nothing happened--64--no result. When I check it the next day, it's still set on a large font (where I left it) but the font is still very small (about a size 8)! Somebody please HELP.

Thank you.

Font size of messages should change with changing settings in Fonts and Colors. However, this does not affect the mailboxes list or the messages list (unfortunately!). If you want to change the font size of the messages list, you need to switch to 'Use classic layout' in Mail/Preferences/Viewing. This was the case in Mountain Lion and hasn't changed a bit in Mavericks, it seems.

Why dont you use Cmd+, Cmd–

This is a standard feature for Mail and Safari as well 😉