That's how the new system works----when you are in the "Conversation" mode. Fortunately------it's easy to disable the "Conversation" option in your settings and that will separate the grouped conversation threads back into single emails---and individually list your emails----(just like it used to). Also---your sent emails won't be in your inbox any longer. To disable it: ON YOUR MAIL PAGE----hover over the "Gear" icon (little wheel thing, top right) and in the drop menu click on "Settings". Then click on "Viewing Emails" (from the menu list on the left) and UN-check the "enable conversations" box. Then click "SAVE".
Same thing happens to me. I don't get it either. Use to just go to the 'sent' box. I have no idea what the new mail is about, and hate it!