Inbox Zero` is a state of having a completely empty inbox, where managing email is no longer a source of stress. To achieve this, one must first define what success means and then develop strategies to manage emails efficiently. Cleaning out the existing inbox by moving all emails into a "DMZ" folder can provide a fresh start. Scheduling regular times to check email and batch processing them is also crucial. The "touch it once" rule suggests making decisions about each email immediately, rather than leaving it to be dealt with later. Using tools like Zapier, which automates tasks across multiple apps, can further aid in managing the constant flow of emails. By implementing these strategies and using the right apps, such as Sortd, Mailstrom, and SaneBox, individuals can defeat email overflow and finally make email more manageable.