Apple iOS Mail does not offer creation of email signatures from HTML. Only a rich-text editing box is provided, without the ability for more customization. HTML Email Signature - Mail enhances these capabilities by allowing customized creation of email signatures from HTML. Simply add your HTML and your signature is created! A button to preview the HTML is also available. ** READ BEFORE PURCHASING ** - Valid HTML must be provided. This is not a design utility. Issues with formatting and/or appearance of the final signature are directly tied to the HTML code.