On your Home page, click the Link button in the editor toolbar.
In the Name field, enter the text for your link. Next, in the Url field, enter your email address in this format: mailto:youremailaddress@your-site-here.net. Be sure to include mailto: at the beginning, with no space between mailto: and your email address.
Click the Update button.
You'll see a new link on your site navigation.
Publish when ready.
Note: Clicking the link in Store Editor will take you to the Edit page for the link. The link will work on your live store.
If you're comfortable with HTML, you can also create an email address link manually. You can enter the HTML for your link into the large text-entry fields within your store, such as the Message, Caption, and Final-text fields. Learn more.