Outlook.com users can add signature to the email message sent from their account using the options available as part of Outlook.com settings.
Step 1: :Login to your Outlook.com account and access More mail settings page (Settings icon –> More mail settings).
Step 2: Navigate to Writing email section and click Formatting, font and signature option.
Step 3: In the Formatting, Font and Signature page, navigate to Personal Signature section. Now you can enter the signature message inside the box. You can also add hyperlink and apply different styles to your signature.
Step 4: After entering the signature, click the Save button to confirm and save the changes.
The signature will be automatically added when you compose new message in Outlook.com