I have Mail.app set up to sync with my Gmail account. I am using IMAP. When I type a message in Mail.app, Mail.app automatically saves the message to the Drafts. This is fine, but if I type another sentence or so, Mail.app will save another Draft, and not rewrite the older draft. My Draft mailbox is huge, and is basically useless, because I have to search for the most recent version of a message. How can I stop this from happening and have Drafts behave normally?