Is there a way to understand meaning of buttons?

I selected all mail and pressed the button with horizontal lines. I thought the button will sort the mail, however, it downloaded them, deleted everything from the mailbox and moved them to the local trash.

I know that to delete mail, I should press the Trash bin button. The button I pressed produced something strange - apparently, the local trash and the mailbox trash are different things, because there is nothing in the trash of the mailbox.

I could not find anything on the button meaning. It seems that to understand what a button does, I have to press it and guess the results.

  1. Dear developers, could you add some guidelines to the help?
  2. Is there a way to move the mail from the trash back to the Inbox folder?

What does this button do?

That’s the button for the ‘archive’ action. It moves messages to the designated Archive folder (see ‘Account settings > Folders > Archive folder’.
You should be able to find out what buttons in the action bar do by long-pressing them. This is not app-specific functionality, it’s provided by Android itself. So there’s a small chance this might not work for you.

Thanks, I didn’t know about this feature.

This g(r)ay flat Metrosexual icons are confusing.