In the "three dot" menu at the top of the conversation, pick "leave".
That will remove the conversation from your folder. When the last person in a conversation leaves, the server deletes the conversation.
There you go. You are way ahead of us. Very easy and concise Thanks Jeff.@jttheclockman
If you leave a conversation it will disappear from your mailbox. The server doesn't delete it until the last person leaves.
If you are not the last person to leave, you will see this:
View attachment 349723
Yes, you can create folders and move messages there. That is not exporting. I made a video about conversation folders.
Exporting creates a file which you can download that contains the conversation in various formats.