A "Send & Snooze" option next to "Send & Archive". I know there is already the ability to click the snooze button, set a time for snooze, then click the send button, but this would be a more elegant solution that would save time and clicks. If it could remember the last time you snoozed for (say I just snoozed an email til 8am next monday morning), and automatically enter that same snooze duration unless told otherwise, that would be even better.