In a new message or a reply in classic Outlook, select  High Importance  
The recipient will see a red exclamation point  
To add a reminder, see Add a reminder to an outgoing message.
Tip: To mark a message as low importance, such as routine FYI information, select  
In a new message or a reply in new Outlook, on the Options tab, select  
The recipient will see a red exclamation point  
To add a reminder, see Add a reminder to an outgoing message.
Tip: The default importance setting is Normal. To mark a message as low importance, such as routine information, select Low.
 
                         
				 
				