How would I mark a message as Read / Seen using this client?

Nov 3, 2013 at 8:13 PM
Edited Nov 3, 2013 at 8:28 PM
Hi All!
How would I mark a message as Read / Seen using this client?

Also, another issue I'm facing is that search results only return ~100 results. If I want to advance to the next set how should i do that?