People typically do one of several things when they receive an email. They read it, delete it, file it, forward it, flag it, respond to it, or ignore it. Outlook won't help you ignore your messages (unless you just delete them), but it can help you with all the other tasks you might want to perform in response to receiving a message.
Replying to a Message
When you receive a message, you can reply to it with or without opening it. You can click the Reply or Reply to All buttons on the toolbar, use the keyboard shortcut Ctrl+R (Reply) or Ctrl+Shift+R (Reply To All), or select the Actions menu and then either choose Reply or Reply to All. You can also right-click the message and select Reply or Reply to All. Reply to All addresses ...