There are several ways for you to read E-Mails. In both the H Split and the V Split view, you just need to click on the desired E-Mail with the left mouse button. It is then displayed in the detail window below or next to the list. Double-clicking on an E-Mail opens this E-Mail in a new window. This makes especially very long E-Mails easier to read.
The
or signs on the left side of the subject allow to open or close the E-Mail header.