This is definitely a great idea, I've been thinking of different ways to accomplish it myself. The research backs this up too as a very reasonable solution, allowing workers to still be productive in replying, while only checking new email at certain intervals.
In fact, you've even come across the magic number for email checking frequency. Checking it 4 times a day provides the best trade-off between reply speed and productivity gain, as seen in research by Gupta et. al.[1]
[1] Gupta, A., Sharda, R., & Greve, R. a. (2010). You’ve got email! Does it really matter to process emails now or later? Information Systems Frontiers
In fact, you've even come across the magic number for email checking frequency. Checking it 4 times a day provides the best trade-off between reply speed and productivity gain, as seen in research by Gupta et. al.[1]
[1] Gupta, A., Sharda, R., & Greve, R. a. (2010). You’ve got email! Does it really matter to process emails now or later? Information Systems Frontiers