mailto links: every parameter (subject, CC, BCC and body) with examples

A mailto link can do quite a bit more than open a blank email. This is the full reference of what it supports and what it doesn't.

Published on October 6, 2026 · By the QLinky team

Structure

A mailto: link has the recipient's address and, optionally, a list of fields after a question mark, separated by &:

mailto:[email protected]?subject=Consulta&body=Hola

Full example

mailto:[email protected][email protected]&subject=Pedido%20de%20presupuesto&body=Hola%2C%0D%0A%0D%0AQuiero%20un%20presupuesto%20para%3A%0D%0A%0D%0AGracias.

That link opens an email to sales, with a copy to support, the subject “Pedido de presupuesto” (quote request) and a four-line body.

Encoding: what fails most

• Spaces: written as %20. The + sign isn't read as a space in mailto and may show up literally in the subject.
• Line breaks: %0D%0A. Two in a row leave a blank line.
• & and ? inside the text: they must be written as %26 and %3F, because unencoded they cut the field short.
• Accented letters: in UTF-8, for example %C3%B3 for ó. The generator takes care of it.

What mailto can't do

• Attach files. There is no standard field for attachments.
• Send the email. It only opens the draft; the person has to send it.
• Format the text. The body is plain text, with no bold or HTML links.
• Choose the program. It opens the device's default email application. If the person uses webmail and hasn't set anything up, nothing may open.

Good practices

• Show the address as text too next to the link, for people who don't have an email application set up.
• Keep the link short. Some programs cut very long URLs. A body of a few lines is safe; a whole letter isn't.
• Watch out for spam. An address published in a mailto link can be harvested by bots. For heavily exposed addresses, a contact form may be better.