How to Modify Email Options in Outlook
Before sending a message, you can add message options to indicate the importance of the message, to notify you if the message has been delivered and/or read, or to delay sending the message until a future date and time.
Some emails are more important than others. To make recipients aware of critical messages, you can mark them with High Importance.
Messages flagged with a priority will display an indicator for High Importance or Low Importance in the recipients’ inbox.
You can find additional message settings on the Options tab of a new message window.
The Useful Email Options table describes the available options.