How to create mailto link in HTML?

Basically, when we usually start with a hyperlink that is Mailto rather than using HTTP or others, the browser should be able to compose an email in the visitor’s default email program on their computer. There are two ways to insert a mailto link into a HubSpot page or email, just by inserting a hyperlink into the rich editor or inputting into the source code. Option one is basically nothing just to insert a mailto link as a hyperlink, also highlight the text or click on the image as you wish.to apply on the mailto link to for your contacts or visitors to click on and finally click Add the link to finish. Option two is to Insert a mailto link into the source code and Click Save to finish then Publish or Update your page.
Example:

<a href="mailto:someone@example.com?Subject=Hello%20again" target="_top">Send Mail</a>