Comparison of Interface
Google offers a different Gmail interface to choose from for their users. However, most of the users find the interface layout unintuitive and cluttered. Gmail has a priority inbox interface, tabbed inbox interface and inbox which allow you to present the emails the way you need them. The tabbed inbox sort the mails into different categories like social, promotions and updates.
Using inbox interface, you can create to–do-list of your mails and mark them as done. You will be able to make a bundle of related messages and snooze the mails which you want to consider later. Moreover, Gmail also offers many tweaks such as preview pane which allows reading the emails without leaving the message list, mark as read button, etc.
Outlook uses a streamlined interface design with three panels. On the left side you can see the categories and folders to navigate and the center panel contains the list of emails and by clicking on the particular email you will be able to read it on the right end pane. However the interface customizing options of outlook.com are very less when compared to Gmail. You will be able to select where the display pane show up or in which order the messages appear during a conversation in Outlook.