JSFiddle - React, Tailwind, and code Playground

HTML

<a href='[email protected]' class='mailto'>User 1</a>
<a href='[email protected]' class='mailto'>User 2</a>
<br>
    Email To: <span id='list'></span>
<a href='mailto:' id='combined' style='display: none;'></a>
<br>
<input type='button' value='Send' id='send'>
<input type='button' value='Clear' id='clear'>

JavaScript

$(document).ready(function() { 
    $('.mailto').click(function(e){
        e.preventDefault();
        $('#combined').attr('href',$('#combined').attr('href') +         $(this).attr('href') + ';');
        $('#list').html($('#list').html() +         $(this).html() + ', ');
    });
    $('#send').click(function(e) {
        $('#combined')[0].click();
    });
    $('#clear').click(function(e) {
        $('#combined').attr('href','mailto:');
        $('#list').html('');
    });
});