Change Viewing preferences in Mail on Mac

List Preview

Choose the number of lines of the message to show in the message list.

Move discarded messages into

Choose where to move messages when you swipe left on them in the message list—to the Trash mailbox to delete them or to the Archive mailbox to archive them.

This setting also determines whether you can delete or archive messages from Mail notifications.

Show message headers

Choose to show default or custom fields in message headers.

To add fields, click the pop-up menu, choose Custom, click the Add button , then enter the name of a message header, such as Return-Path.

Display unread messages with bold font

In column layout, show unread messages in bold to help distinguish them from messages you have read.

Use Smart Addresses

Show recipients’ names but not their email addresses (if a recipient is in the Contacts app or the Previous Recipients list, or on a network server).

Use dark backgrounds for messages

Show messages in the preview area and new messages you’re writing with either a dark background (select the checkbox) or a light background (deselect the checkbox). This option is available only if you set Appearance to Dark in General System Preferences.

When this checkbox is selected, you can switch to a light background while viewing or writing a message. Choose View > Message > Show with Light Background. To show the message with a dark background again, choose View > Message > Show with Dark Background.

Highlight messages with color when not grouped

When email conversations are turned off, highlight the messages in a conversation in the message list, to help identify them more easily. Click the color well to choose a highlight color.

Include related messages

When viewing a conversation, show related messages (those located in other mailboxes).

Mark all messages as read when opening a conversation

Mark all unread messages in a conversation as read when you view the primary message of the conversation.

Show most recent message at the top

Display the most recent message in a conversation first in the preview area. If the checkbox is deselected, the oldest message appears first.