trash vs junk: How are those 2 folders defined and what goes to them? Are there settings ?

What determines which emails go to Junk versus which ones go to Trash ?  I have been unable to find related settings.   Of course one can intentionally MOVE messages to either folder but how do they get there otherwise?  I’m hoping there is no automatic movement of messages I may want to keep after some set time, etc.   

Trash is the bin. This is where messages go when you delete them.

Junk is the spam folder. With a synced account like Google, the server will automatically move spam messages to this folder. Some servers don’t do that, but they do add a message header to indicate the message is spam. In that case eM Client’s Spam filter Rule will move these messages from your Inbox to the Junk folder. Sometimes you receive newsletters or other unwanted messages that are not technically spam, but you really don’t want them. In that instance you can setup a Blacklist Rule (by right-click on the unwanted message and choosing Move to Junk) to move messages from that sender, or the sender’s domain to Junk. The Spam filter Rule and the Blacklist Rule (if enabled) will be in Menu > Tools > Rules. You can’t edit the Spam filter Rule but you can disable or remove it.

Other than that, messages cannot move to either of these folders on their own.

Good info.  Appreciate it.