I wasn't seeing any way to empty the trash on my webmail. So I went looking on the Internet for the steps to empty trash on roundcube, and right away noticed the problem. The gear icon with the "empty" option wasn't there. I switched the skin from Elastic to Larry, and it was back.
Also, I don't see any way in the Elastic skin to get a folder list on the left side. That's something I really like having, and would like to see in a future version. The other skins don't seem to have a dark mode, which is why I was using Elastic.
Just upgraded to 1.5.2, was on 1.4.11. The upgrade didn't change anything.
Empty option is in the Elastic skin just click on the three dots at the top of the folders list and select empty.
I never would have found that without assistance. That solves one problem.
I logged into a different account that has LOTS of folders. It had "inbox" selected. Unlike the account I was initially using for testing, this one showed the whole folder list in the middle pane after I logged in. I clicked the three dots and then "Empty". It said it was going to delete all messages in "this folder" ... which before I clicked the three dots, was the inbox. There are over five thousand messages in that folder. I did not confirm the delete. If it meant that it was going to empty the trash folder, it should say so.
If I click on any folder in the folder list, then the folder list disappears. I really want the folder list on the left side, and for it to not disappear when I choose a folder. This is how the other skins behave.
The folder list doesn't disappear after a folder is select unless your on a smaller screen size it witch case it works as designed because of the responsive design to support mobile devices.