A lot of users prefer Threads view over the standard List view of email messages in the mailbox.
Here's how to activate Threads view in RoundCube "Elastic" theme and how to sort the messages by arrival date.
Video Link: https://www.youtube.com/watch?v=4phL-VxpHj8&list=PL6n6RAoV8lniwrKQWaLNz2jxbcuHLnm87