We get mails from our colleagues day in and day out. If you are using Lync in your enterprise, it will also let you know whether the person who sent the mail as well as others who have received it are available online at the moment through the presence indicator which glows green close to the email addresses of the people. (Grey indicates the concerned person is offline for quite a while, yellow indicates he is temporarily offline and red indicates he is busy).
Now, if you want to clarify a point immediately and you don't want to do it through a reply to the mail, which might take relatively more time, then your tools come in handy immediately. As Outlook is closely integrated with Lync, striking a conversation with one or more people in the mail can be done in just a click of your mouse.
Just point to the email address and you are presented with an option to start an instant messaging (chat) session, an audio call, a video call or a reply mail. Click the IM icon and your IM window opens for a chat session. You can drag and drop other emails into the chat window and include them in the chat. You can also use the IM option in the Respond cluster of the Home tab of the Outlook Ribbon to Reply with IM or Reply all with IM.
You work gets done quickly and your productivity increases manifold when you start using this feature.