http://thegreyblog.blogspot.ca/2009/06/configuring-evolution-for-gmail.html
- Basically, every label becomes a folder.
- You can label a message by copying it into the corresponding folder.
- If you move a message, you remove the label from the originating folder and replace it with the destination.
- Inbox is a label and a folder.
- To archive something from the inbox, just move it away from the Inbox folder/label, which can easily be done by deleting it, moving it to the Evolution trash (but not the GMail Trash label/folder).
- Deleting a message only removes it from the folder you're immediately deleting it from (removing that label), and because all mail arriving in GMail is automatically labelled with All Mail, you still retain a copy there.
- If you want to truly delete a message, you'd label it with GMail's Trash label (move or copy it into that folder).
- It will actually stick around in your other labels/folders for 30 days (unless you remove it from each one), but then be completely purged from GMail (and thus the other labels).