Editing Mailto (section)

==Security and privacy==
{{see also|Address munging}}

A number of security issues are mentioned in [https://datatracker.ietf.org/doc/html/rfc6068#section-7 RFC 6068], one of them being robotic [[address harvesting]]. Mailto constructs are locatable within HTML pages by automated means which typically include the use of [[Document Object Model|DOM]] constructs or [[regular expression]]s. Addresses harvested by such means are liable to be added to [[E-mail spam|spam]]mers' mass-mailing lists and thus to receive large amounts of unwanted mail.

While methods exist to "harden" mailto links against harvesting—[[address munging]] and [[JavaScript]]-based address [[Obfuscation (software)|obfuscation]] among them—these protections can be circumvented by sufficiently sophisticated harvesting robots.  Other techniques, like walling the address behind a [[CAPTCHA]] or similar "humanity check", provide security on par with that available for other contact methods, most notably [[Form (HTML)|web forms]], which experience similar challenges with preventing spam.