Try Open URL extension with mailto:john@mail.com as the URL. Keep in mind that how mailto links are opened depends on a user configuration (what browser, system and email program is used) and website author doesn’t have a control over it.
Thanks @jan but it doesn’t work for me on all platforms , on my computer opens a page with the address mailto:john@mail.com and nothing else, on the cell phone, opens the mail application , I’ll have to write something different? or is it something from my computer as you say!
If a computer is not configured to open mailto links with an email client, there is nothing a website can do to open the client when such link is clicked. This is why contact emails on websites are often clearly shown so visitors can copy-paste them if mailto link is not working for them.
In Shapespark case, it could be better to use the HTML Label extension to show the email address as a mailto link:
Contact us at <a href="mailto:john@mail.com">john@mail.com</a>.
This way the email is visible and can be copy pasted if mailto is not working.
You can change the appearance of the link with inline CSS style for the a element. For example, to display the link as bold blue text without underline use: