A mailto hyperlink is one that opens default mail clients so that you can send an email to somebody. For example, if your default mail client was Outlook Express that would open when you click on a mailto hyperlink. You can quickly set up an HTML mailto hyperlink for your website from the RapidTables site.
Open this page  on RapidTables to open the generator in the shot below. The generator is at the bottom of the page. It includes a few fields you can fill out to set up the mailto hyperlink.
First, enter the anchor text for the hyperlink in the Link text box. That’s the text included in the hyperlink. Below that is a To field where you should input the email address for the mailto hyperlink.
The other fields are not essential. They include CC, BB, Subject and a Body text boxes. If you fill them out, the default email client’s text editor will open with those fields filled out.
Pess the Generate mailto code button. Then the HTML code for the mailto hyperlink is included in the text box below. Select the code and copy it by pressing Ctrl + C, and then you can paste it into your website HTML with the Ctrl + V hotkey. A Generated link view box includes a preview of the mailto hyperlink.