A draft you save now appears in the Drafts list right away, without a manual refresh, and empty drafts are no longer kept, with the save button disabled when there is nothing to save. The compose screen is tidied: the address and subject fields are tighter and aligned, the subject shows as a hint that clears as you type, and a stray band above the keyboard is gone. You can now view a message's raw headers from its menu. A new reply brings an archived conversation back to the inbox by default. The automatic refresh when your connection returns now also works when the system's connectivity checks are switched off.
