Don't try to manage deliverables by email. Instead have your assistant have one excel spreadsheet where he or she puts everything.
For one, creating the space for downtime increases productivity. Subject to heavy workloads and never-ending to-do lists, it’s easy to put our heads down and charge through tasks, thinking we have no time for days off, free evenings, or weeklong vacations. But driving too hard without breaks can make us less productive and less focused.