>When I click on Reply button (on dashboard) I see all replies that I received. How do I see only replies from one person? (I am looking for an old message and can't find it). I see the First Name, Last Name criteria at the top of the list. But I can't figure out how to use them; that is, to make the list filter on the entered values.

You can filter on one column only. Type a last name, for example, and hit Enter. You can also sort by a column and than scroll/page to the appropriate line.