Estimate daily email time.
Email time has two components with very different remedies. Replies scale with how many messages genuinely need one, and are reduced by writing shorter or delegating. Triage — opening, reading and deciding — applies to every message regardless, so at ninety messages a day even twelve seconds each is eighteen minutes of pure sorting. The triage share tells you which of the two is actually consuming your day.
Email time split
Reply minutes = received x reply share x minutes per reply; triage minutes = received x triage seconds / 60; annual hours = daily minutes x 5 x 46 / 60
Studies of knowledge work consistently find two to three hours a day, or roughly a quarter of the working week. The figure rises sharply with seniority and with the number of projects a person is attached to.
Cutting inbound volume. Unsubscribing, leaving low-value distribution lists and moving status updates to a shared channel reduce both triage and replies, whereas typing faster only touches the reply half.
It reduces the interruption cost rather than the time. Two or three defined email blocks a day leaves the same minutes on the task but removes the constant context switching, which is where most of the hidden productivity cost sits.