Outlook message window does not show all message fields. There many fields hidden behind the Options button, where you can set message priority, delivery notifications, etc.
If you want to be sure that someone has received your message, you can request a delivery receipt.
Usually Outlook users are using folders to organize messages, but you can also use colors. For example, you might apply a special color to all messages from a particular person. You can then see at a glance which messages are from that person.
In Outlook 2013 you wouldn't find a distribution list because it's called now Contact Groups, for more details see How to import a Contact Group sent you as an attachment.
Outlook proposes next shortcut keys for easy and quick work with e-mails: