JSFiddle - React, Tailwind, and code Playground
HTML
<div id="counter">0</div>
JavaScript
var emailsToSend = 10;
var counter = document.getElementById("counter");
var interval = setInterval(function() {
counter.innerHTML = emailsToSend;
if (emailsToSend === 0) {
clearInterval(interval);
}
emailsToSend--;
}, 150);