The new features at Yahoo allow you to check your login activity. If someone logged in to your Yahoo account without your permission, you could check it. After checking it, you can remove the login device and change your Yahoo account password. To delete recent login activity in Yahoo Mail account, open the Yahoo Mail app, tap the human icon from the upper-left corner of the Yahoo mail app and select the Manage accounts option. To view your recent login activity, tap on the Account Info tab and tap Recent Activity. The previous login history will open, and a sign-out button will appear in front of the login device. Now, press the sign-out text link to delete login activity in the Yahoo account from this device.