What is Mailto?

The mailto: protocol is a specialized URL scheme used in HTML and email. The protocol creates a hyperlink that opens the user’s default email client, pre-populated with specific email details such as the recipient’s address, subject, and body text. 


The mailto: link simplifies communication by enabling a quick and direct way to initiate email correspondence without needing to retype the address.



Development of the Mailto: Protocol


The mailto: protocol was established as part of the internet’s core set of schemes in the early days of the industry. It was defined in 1992 in RFC 1341, part of the MIME (Multipurpose Internet Mail Extensions) standard, designed to facilitate email communication directly from webpages. 


As the internet evolved, so did the capabilities of the mailto: protocol, expanding its functionality to include additional fields like CC, BCC, and body content, which were standardized in RFC 2368 in 1998.



How Does the Mailto: Protocol Work?


The primary function of the mailto: protocol is to create hyperlinks on web pages and emails that users can click or tap on to send an email without manually entering the recipient’s email address. A typical mailto: link can include several parts:

  • The recipient's Email Address:

    The most basic mailto: link includes the intended recipient’s email address. For example: <a href=”mailto:example@example.com”>Send Email</a>

  • The Subject Line:

    Developers can pre-populate the email’s subject line by adding a subject parameter to the mailto: link. For example: <a href=”mailto:example@example.com?subject=Feedback”>Here is my  opinion</a>

  • Text in an Email Body:

    The body of the email can also be pre-filled using the body parameter. This is useful for standardizing messages. For example: <a href=”mailto:example@example.com?body=Hello%20World”>Unsubscribe Me</a>

  • Additional Recipients:

    The mailto: link can include CC (carbon copy) and BCC (blind carbon copy) fields to add additional recipients. This is done by including cc and bcc parameters. For example: <a href=”mailto:example@spikenow.com?cc=other@aol.com&bcc=another@pizzahut.com”>Email Us</a>


Common Uses of Mailto:


The mailto: protocol is heavily used across various applications and use cases today:


  • Websites: Contact pages often use mailto: links to give visitors a quick way to reach out to the business or the webmaster.


  • Emails: Email newsletters might include mailto: links to facilitate easy responses from recipients to reach out to someone.


  • Documents: PDFs and Word documents often include mailto: links in digital resumes, reports, and publications to allow for easy contact to connect with

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