When it comes to free webmail services, there are two services that pop-up in our mind instantly. One is Google’s widely used Gmail and other one is Microsoft’s popular Outlook.com. While Yahoo! Mail was once a popular webmail service, most users have either closed down their email accounts or switched to Gmail, Outlook.com or other email services for a number of reasons, including the cramped user interface. Over the last two or three years, in an attempt to gain its lost users and stop users from switching to other webmail services, Yahoo! has improved its Mail service by adding a number of features. A better spam filtering system, two-factor authentication, and better user interface are some of the key improvements that have been made in the last two or three years. While there is no doubt that its competitors, mainly Gmail and Outlook.com, are offering more number of features and services, Yahoo! Mail is definitely improving with time. Though Yahoo! Mail isn’t as customizable as Gmail, you can change the default look of your inbox by choosing a new theme. If you already own a Yahoo! Mail account and want to personalize it by changing the default background, you can do so by following given below instructions. Customizing Yahoo! Mail Step 1: Sign-in to your Yahoo! Mail account. Step 2: On the upper-right of the page, click on the Gear icon and then click Themes. Step 3: Choose one of the available themes to change the current background and theme. Unfortunately, Yahoo! Mail doesn’t let you set your own image file as Mail background picture as of now (one can set custom picture as background in Gmail). However, you can choose one of the tens of gorgeous backgrounds to personalize your inbox. We are sure that you will definitely fall in love with the new look of your inbox. And if you’re on Windows 8/8.1 and have downloaded official Yahoo! Mail app, how to sign-out in Yahoo! Mail app guide might also interest you.