Too many colours.
Everything is just ... In the face. Sometimes, simpler is better.
Lindy T commented
Keep classic version available forever
I like to be able to skim at a glance, and there's too much clashing information to be able to do that
Keep to one colour scheme and don't think a preview of attachments is helpful. More distracting when deciding what to action first.
That pinned mails are now collapsed works fine :-)
However, I dislike that all emails now have the user-symbol of the sender [of an email] in my inbox.
The old inbox is pleasant (colorwise), since there's not a lot of noise; the colors are pleasant and does not remove focus.
But the new one is filled with icons containing the senders user icon, and it creates a lot of noise and removes the focus from the task at hand.
Please add an option to remove user icons.
Also, stop increasing the font size.
The colours hurt my eyes. I would prefer a black and white mode
Louise Sar commented
It is harder to see things than in the previous version, there is too much visual clutter on the mail interface. and things seem to take up more space, I feel I was scrolling more than usual to see my folders etc on the side bar.
Riot of colours. Far too distracting. By all means have a facility where you can configure colour options but keep it simple and easy to read.
Alina Wim commented
Please use less colours