Mailto

mailto is a Uniform Resource Identifier (URI) scheme for email resources. More specifically, mailto URIs identify resources reachable via network mail, thus a mailto URI designates one or more mailboxs via use of email addresses. Clicking on a mailto link opens an email client in compose mode, typically with one or more pre-filled form fields.

A common use is to produce hyperlinks on websites that allow users to send an email to a specific address directly from an HTML document, without having to copy and enter it into an email client.