First step of email actions

Just to have some feedback before going further
I don't say "it's bad because it's GMail", but that GMail is unique in the way it manage folders. Gmail don't use mailboxes, only labels (a concept that doesn't exist in IMAP. Gmail use a custom message header).

Every other IMAP provider uses folders (mailboxes), and their users are used to manage messages like files in a folder tree. So in my opinion this is not a UI decision. But you're right, let's ask the crowd ;)