If you receive a high volume of messages, it is easier for important messages requiring your attention or follow-up to get lost or overlooked in your Inbox. Outlook lets you flag messages in your Inbox, thereby alerting you to their importance and reminding you that the message requires some follow-up.

To flag a message in your Inbox, right click the appropriate message and click Follow-up. The Flag for Follow-up window will appear. Use the drop down arrow beside the Flag to value to select the action required for the message. You can also set a due date which is helpful if you need to follow-up by a certain date. Once you have set the appropriate follow-up options, click OK. The message will appear with a red flag beside it.

To remove the message flag, right click the message and select the Clear Flag option.