When, on second thought, you’re not finished with an email and want to take another look at a later time, you can mark it as unread again. One of the easiest ways to do it, especially if you used a Keyboard Shortcut to mark the message read in the first place, is by pressing Shift + K on your keyboard.

But of course, there are other ways you can do it as well. Here are all the ways you can mark a message unread in Vivaldi Mail:

• Click on the  Mark Unread button in the message toolbar above the message.
• Right-click on the message in the message list and select Mark Unread.
• Use the Keyboard Shortcut Shift+K. To mark the whole message thread unread, press Shift + M.
• Type “Mark Messages as Unread” in Quick Commands.
• Create a Mouse Gesture for the action.