Gmail puts the newer emails first as follows:
- anita@openmailbox.com | Dogs issue | 19:40
- pepito@hotmail.com | Important facts from Jupiter | 14:03
- juanito@gmail.com | You coming? | 09:25
Everything else (already seen email)
- tsstss@openmailbox.com | Dinosaurs still exists! | 17:13
- jaja@hotmail.com | Yep or Nope | 14:08
- blabla@gmail.com | Whatever? | 09:27
I think it is better to start reading the oldest non-seen emails:
- juanito@gmail.com | You coming? | 09:25
- pepito@hotmail.com | Important facts from Jupiter | 14:03
- anita@openmailbox.com | Dogs issue | 19:40
Everything else (already seen email, same order: first the newer email)
- tsstss@openmailbox.com | Dinosaurs still exists! | 17:13
- jaja@hotmail.com | Yep or Nope | 14:08
- blabla@gmail.com | Whatever? | 09:27
Is it possible? How?
UPDATE (from comments)
Gmail does not have an option for that. However, maybe there are some Greasemonkey scripts able to do that. Or some Chrome or Firefox extension.