How can I stop 'bin' items from appearing when searching Mail.app?
Per http://productforums.google.com/d/msg/gmail/ZHgilTVP7ts/bpIWgcLAzrUJ


  The Bin holds deleted messages, so it should not normally contain all of your received and sent mail. If it does, there is a problem. Apple Mail does not handle drafts on the server well, and leaves the fragments behind. To avoid that, change the setting in Apple Mail to save drafts locally, not on the Gmail server.