If you want to change the columns in the mail message list, right-click on the column headers and choose either Add a Column… or Remove This Column.
If you have a small display, you can replace the Subject column by the Subject - Trimmed which will remove prefixes such as "Re:", or you can replace the From column which displays the sender's name and email address by the Sender column which will only display the sender's name.
If you would like to have the same column layout in all mail folders except for the Sent folder, you can enable Edit ▸ Preferences ▸ Mail Preferences ▸ General ▸ Apply the same view settings to all folders. Note that this setting also influences Group by Threads and the Message Preview visibility in all folders.
Got a comment? Spotted an error? Found the instructions unclear? Send feedback about this page.
