Do you want an email address in the form that opens a new email when clicked? Like a mailto link in HTML?
If so, just select the email address text, right-click, insert hyperlink, and type in mailto://<email address>
In the Design tab add a formatted text field to your form. In the formatted text field select the text you want to create a link with. Go to menu Insert-> Link... In the Insert Link dialog you will add an email address to the bottom field (URL or Email) and click on the Insert button. The email address should be in the form of email@example.com.