For a developer there shouldn't normally be a need to check email that often (if good processes are in place), but if you're doing sales, support, fundraising,

For a developer there shouldn't normally be a need to check email that often (if good processes are in place), but if you're doing sales, support, fundraising, etc., then seeing and responding to incoming emails quickly can be very important. It's crazy how much difference in conversion rate you can see by responding to a lead in 5 minutes vs. even a few hours, or how much more forgiving customers are of problems when you respond very quickly.