Look up emails by date
iPhone 6s Plus, iOS 10.3.2
iPhone 6s Plus, iOS 10.3.2
On your iphone, open the e-mail box you want to filter (for example inbox).
Then, in the search bar at the top, start writing a date, and look at the automatic results that appear....
I think you can do it only by months, but... better than nothing.
Regards
Giulio
See also this support guide:
Find and organize emails on your iPhone, iPad, or iPod touch - Apple Support
Giulio
Look up emails by date