CODE EXAMPLE FOR HTML

html email signature code

<a href="maito:youremail@gmail.com"><button>email me!</button></a>
or
<button onclick="document.location = 'maito:youremail@gmail.com'"></button>

NOTE:
you can always replace <button> with a text element like <p> or <h1>. I reccomend
  the first line of code if you are unsure of which one you should use.