Apple Mail defaults to show you a sizable preview of the messages in your inbox, but all that information takes up a ton of space. Fortunately, things were once simpler, and by turning on Classic Layout, you can see more of your inbox at a time.
This is a great way to take care of email in large chunks, so you can select a batch to archive or mark as read. It's also useful for helping you find the important messages in a sea of newsletters, spam and other digital detritus.
Here's how to switch Apple Mail to Classic Layout:
1. Click Mail.
2. Select Preferences.
3. Click Viewing.
4. Click use classic layout.
Now you've enabled classic layout. Isn't it easier to see everything now?