JSFiddle - React, Tailwind, and code Playground

HTML

<div id="env">
     <form>
         <textarea id="email" placeholder="email-da-pessoa@servidor.com"></textarea>
             <input type="button" id="execute" class="btn btn-success" value="Executar NewLast">
        </form>
        <hr>
        <div class="alert alert-dark" role="alert">
          E-Mails Enviados: 01
        </div>
        <div class="alert alert-success" role="alert">
          Enviado com sucesso para: luanlucas@outlook.com
        </div>
    </div><!--env-->

JavaScript

$("#execute").click(function(){
    var email = $("#email").val();
    var index = 0;
    splitemail = email.split("\n");
    
    splitemail.forEach(function(value){ 
                                         alert("O tempo de espera Ă© : "+(1000 * index));
                                         setTimeout(function(){ alert(value); }, 1000 * index);
       index = index + 1;
    });
});