How do I change the 'Reply To' email address for MS Mail App on Windows 8.1

Step 1: On the Start screen, tap or click Mail.

Step 2: Swipe in from the right edge of the screen and tap Settings.
(If you're using a mouse, point to the top-right corner of the screen, move the mouse pointer down, and click Settings.)

Step 3: Tap or click Accounts.

Step 4: Tap or click Add an account, choose the type of account you want to add, then follow the on-screen instructions.

If you still have trouble, seek our expert's help from the following chat link.

If the issue is still not fixed, it can be a very critical problem with your computer affecting your personal data and the Windows Operating System. You will have to chat with our Experts or you can check with your local technician to get the problems fixed with very high priority.