Mail text in columns bigger

The column and contents of that column "sort by" is in a quite small font which I would like to make bigger. I know how to enlarge the font in the mail itself but not the summary data which appears in the column which indicates who the mail is from and the first two lines of the message.
Any ideas?
Thank you

You'll need to use a utility such as TinkerTool to do what you want. Be sure to read the directions as changing the font on menus will impact some other menus throughout the OS.