You can’t set as many options for an individual message in Outlook.com as you can in the regular version of Outlook: only message priority and file format. Just follow these steps:
Click the Inbox in the Folder list.
Click the New button in the Ribbon.
Fill out the New Message screen.
Put your recipient’s address in the To box, a subject in the Subject box, and the message in the main box.
Click Options in the Ribbon.
The Message Options dialog box opens, showing the options.
Choose the options you want.
Click the Send button.
It’s a good idea not to overuse the message options. Setting all your messages to High, for example, eventually leads people to ignore your priority markings. (“Oh, she thinks everything is urgent; just ignore her.”).
In fact, sometimes it’s wise to mark a message as low priority. That tells the person you’re contacting that you respect her time, but that you also want to keep her informed. A little courtesy goes a long way.