The signature field in Webmail:Preferences now supports rich text (HTML), and you can format your signatures using the buttons below the field.
Note that each folder can have its own set of preferences, so you can set one signature per folder. When writing a new message, the signature that was set for the corresponding folder profile will be inserted, and can be manually updated to that of another folder profile (by using the “Update sign.” button in Compose).
What are the step by step instructions to edit the signature that’s already there?