With large monitors increasingly common in offices, many Outlook users use the Reading Pane to read messages and they seldom double-click on a message to open it.
Some people don’t want Outlook to mark a message as read until they have read the whole message. Taking a quick peek at an email in the Reading Pane should not mark it as read. They use the Unread mail view to then focus on the messages they have not read.
When you view a message in the Reading Pane, Outlook lets you specify how many seconds to wait before marking it as read.
To change how long Outlook waits before marking an email as read:
With the Reading Pane turned on, View tab, Layout group, Reading Pane button
- Select Options
- Select Mark items as read when viewed in the Reading Pane
- Optionally, change the number of seconds
- Click on OK