Create an email signature from a template - Microsoft Support
To resize the image, select the image to see drag handles appear around the image. Move the drag handles to resize the image as necessary. Select the Picture Format tab on the ribbon, then use the options on it to format your image. For example, you can apply a style or a border to the image.
Applies To:
Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016