In Outlook 2013 and Outlook 2016, the sender is shown in a bigger font that the subject in the email list. This is a change from Outlook 2010 where both lines were with the same font size.
To get that behaviour back, do the following:
- Go to the View tab
- Click on View Settings
- Click on Conditional Formatting...
- Click on Add and give the new rule a name (e.g. "Sender name")
- Click on Font...
- Under the "Size" heading, click on Smaller
- Click OK
- You will get a warning that you have not created a condition. Click Yes