The best time of the day to work is early morning, whilst your brain is fresh and you don’t have the distractions of calls/emails/meetings.
Why would you use this precious time to clear your email inbox?
It’s like pouring a fine bottle of Bordeaux into your stew as flavour.
A waste.
Wake up early, and use your best hours of the day to do your most important thinking/work.
Business plans, strategy, sales pitches.
Leave your email till the day gets crazy.