Office 365 (Outlook on the web) - Actions you can take from a contact
Every contact that you see in Outlook Web App will have links for actions that you can take directly from that contact. Possible actions may include sending a message, inviting them to a meeting, or starting an IM session with them.
To send a message, select the message icon.
To start an IM session, select the IM icon.
To create a meeting invitation, select the calendar icon.