You can set a priority for your message or reply.
To set a message priority you must be on the page where you type your message or reply.
On the Priority drop-down list, select the priority for your message or reply.
The options are Normal (standard), High, and Low. Message priority status is shown in both the Inbox and Sent Mail views.
High priority - shown by an exclamation point (!).
Normal priority - no indicator.
Low priority - shown by a blue down arrow.
When you reply to a message, the reply priority is automatically set to the same level as the message, but you can select a different priority for your reply.