A mailto link is a special type of hyperlink that, when clicked, opens the visitor's default email application with a new message already addressed to a specified recipient. Instead of pointing to a web page, its href uses the mailto: scheme followed by an email address, turning a simple link into a one-click way to start an email.
Beyond the recipient, mailto links can pre-fill many fields through URL parameters. You can set a subject, body text, and cc or bcc recipients by appending them as query parameters, letting you hand visitors a ready-to-send message that only needs their personal touch - useful for support requests, feedback, or structured inquiries.
Values in these parameters must be URL-encoded, because subjects and bodies often contain spaces, line breaks, and punctuation that would otherwise break the link. Spaces become %20, line breaks become %0A, and so on. Getting this encoding right is what separates a working pre-filled link from a broken one.
Mailto links are convenient but come with a caveat: because the address is written in plain text in the page source, scrapers harvest it easily, which can attract spam. They also depend on the visitor having a configured email client. Despite these limits, they remain a clean, dependable way to invite direct contact.