I accidentally moved an email into the trash folder. I found it immediately and clicked on "move" and tried to return it to the inbox. It has now disappeared completely. I then tried to move some unimportant emails from other folders back to the inbox and they have all gone as well. I am sure I used to be able to do this.
When you use the Move function in webmail, it appears that you will be putting something in the Inbox - highlighted in red. But the target folder is actually the last one you moved something to. In this case Purchases, highlighted in grey. If you have a lot of folders, the target folder can be below the visible screen. I hope this is what happened for you - have a look in the target folder!
I had to take a photo, as choosing the screen snip tool made the red line go away.