Generally speaking, the faster someone responds to emails the less progress they are making.
It makes sense. In many cases, people who don’t quickly respond to emails are busy honing their craft. They are making their art, serving their clients, out and about. The plan their day in advance rather than let emails hijack their time.
If left untamed, email is relentless. Emails appear incrementally throughout the day. Keeping an email programme open means dealing with one at a time. It costs attention and focus and is paid for with lack of progress.
The more emails you send the more you’ll get back. You become known for your responsiveness, so people send you more. They think less about the content because your reply is certain to come. This spirals out of control and you feel overwhelmed by your inbox. Even less progress is made.
Batching. Switching it off. Being less responsive. Carving out time for what you really need to do.