JSFiddle - React, Tailwind, and code Playground
HTML
<p class="mailme">some <br>AT <br>email DOT com</p>
<p class="mailme">some AT email DOT com</p>
JavaScript
var mailme = $$('.mailme'), at = / AT /, dot = / DOT /g;
mailme.each(function(el){
var addr = el.get('text').replace(at, '@').replace(dot, '.');
new Element('a', {
href: 'mailto:'+ addr,
html: addr
}).inject(el, 'after');
el.destroy();
});