In each of our courses, we have a section where the students introduce themselves and share some parts of their background and expectations for the course.  I make it a practice to answer each of these discussion posts within a day of posting.  In fact, I generally get online multiple times a day to answer them as soon as possible after posting.  I try to establish some level of rapport with each student by sharing something about their message that resonates with me.  I am a Navy Veteran and 80% of my students come from a background that is similar to mine, so that makes some rapport easy.  However, more and more often, most of my students are more the age of my grandchildren.  This has meant that the exchanges are often learning experiences for both of us.  I think that actually makes the process more fun.