There are some people who intuitively understand and have the discipline to not be interrupted, and there are others who allow themselves to be interrupted continually. The ding or the flash of a newly received e-mail is like newfound treasure.
You can tell who is allowing that invasion by how quickly they respond to an e-mail you send them. If they respond within minutes, they are not being as productive as possible — they are looking up every time a new e-mail message comes in. Of course it’s okay to have this happen infrequently, but those folks who continually respond immediately are most likely not getting anything else done.
If you want to know who needs the most help managing their inboxes, the answer is easy. Just find those people who respond immediately – not just once or twice, but consistently.