a (really) simple way to hide mailto to bots

mailto.js

;[].forEach.call(document.getElementsByClassName("js-MailTo"), function(el) {
  el.setAttribute("href", "mailto:" + el.getAttribute("data-mailto-user") + "@" + (el.getAttribute("data-mailto-domain") || window.location.host))
})

mailto.js.html

<!-- will create a href="mailto:hello+from-website@{current domain}" -->
<a class="js-MailTo" data-mailto-user="hello+from-website">this is a mail to a user from this domain<a/>

<!-- will create a href="mailto:hello+from-another@domain.com" -->
<a class="js-MailTo" data-mailto-user="hello+from-another" data-mailto-domain="domain.com">this is a mail to a user with his own domain<a/>

Clever : i used to regex on the regex, but yours stays accessible.