Folders Vs Labels

Traditional folders force each email into one category. Labels (used by Gmail) let you tag an email with multiple categories. Neither system is objectively better; what matters is consistency.

Keep your system minimal. Three to five action categories is plenty: Action Required, Waiting For Reply, Reference, and Delegated. Resist the urge to create a folder for every project or client. Over-categorizing creates its own maintenance burden and eventually collapses under its own complexity.