Microsoft Outlook 2013 allows customizing font size used to show sender date, name and sub in message list. May be you need to just change size to make font big or small in size or change font size to one you like better.
To change font setting of Message list, Open Microsoft Outlook and Click to “View” tab
Step 1: Simply click on the “View Setting” button in Current View section of View tab.
Click on Conditional Formatting available in Advanced View Setting dialog box.
Click on Add button to add a new rule available in Conditional formatting dialog box
Enter New rule name, like: “List Font Size”, in Name Edit Box and after that Click font.
Change Font size, style and other setting such as color and effects according to your desire. And after that Click Ok if you make changes
In this step, we are introducing same font size to message list all parts such as (sender’s name, date received, and size, subject etc), we are not defining a condition. Dialog box exhibit warning of fact. Click on Yes button.
Font for each message all part in message list is change to the size and font you selected.
Rule can be deleted you made to go back to default setting or it can be deselected on “Conditional Formatting”