Your signature should now be active in your Outlook Online. When you are done, click Save at the bottom and simply close the settings screen. If you want to include your signature automatically in your emails, then make sure you select the two checkboxes below the text area. Automatically include the Signature in Outlook 365.You can create or paste your signature in the text area. You will now see the Email signature settings. Add the bottom of the settings pane, select View all Outlook settings.Select the gear icon on the right side in the top bar.To add a signature to your emails in Outlook 365 (Outlook Online) you will have to open Outlook in your web browser: