Productivity and engagement killer: Mobile e-mail.

Stop and think about this for one second, and try to follow this bouncing ball:

• A lot of people (probably a majority) do check their e-mail at off-hours, i.e. night-time at home.

• When they're doing that, a subsequent large number are probably doing it via their phones.

• They may respond to a few -- usually from people above them, if I had to guess -- but mo…