How to Turn On or Off and Change Signature in Mail App in Windows 8 and 8.1
The Mail app included in Windows 8 automatically adds the signature "Sent from Windows Mail" to the bottom of all of your new email messages.
This tutorial will show you how to turn on or off and change your signature in the Mail app in Windows 8, Windows RT, Windows 8.1, and Windows RT 8.1.
1. Open the Mail app from the Start screen.
2. While in the Mail app, open the Charms bar, and click/tap on the Settings charm. (see screenshot below)
NOTE: You could also press the Windows + I keys to open the Settings charm.
3. Click/tap on Accounts. (see screenshot below)
4. Click/tap on the email account that you want to change the signature for. (see screenshot below)
5. Do step 6 or 7 below for what you would like to do.
6. To Turn Off Using an Email Signature in Mail App
A) Under Use an email signature, move the slider to the left to say No, and go to step 8 below. (see left screenshot below step 7)
7. To Turn On and Change an Email Signature in Mail App
NOTE: This is the default setting.
A) Under Use an email signature, move the slider to the right to say Yes. (see right screenshot below)
B) If you like, you could type whatever text you like in the box to be your signature for messages sent by this email account.
8. When finished, you can click/tap on an empty area in the Mail app to close the email account flyout. (see screenshots above)